It's weird then that many of the top Japanese and American players have dropped Brawl. It doesn't suit many players styles because it has very real problems. I'm not saying it doesn't have depth, but M2K, whose inarguably the top Smash player overall, says that Brawl has the capacity to be really really lame, and while he's tired of Melee, it has really ridiculously high potential as a game even ten years later.
I mean, Ally and Otori and plenty of other really high level Brawl players have long fled the game like rats from a sinking ship. Don't you think that says something about the games longevity? That it's top players quit it? That it had to drastically change its tournament rule set to keep interest and that still didn't really work out?
The more differences Smash 4 has to Brawl, the better, I say.
Brawl had tripping, which was a really annoying, and poor design choice which added this random factor. Players have lost grand finals of tournaments because of tripping.
It had really widespread chaingrabbing that didn't require reading DI, which just lead to the invalidation of a large part of the cast.
It had metaknight who really outclasses most of the cast, and is only kept up with by a few gimicky characters.
Now if it's top players want to stop playing and switch to other smash games, and the top overall Smash player rates it as his second least favorite Smash game, right before 64 which he says just has a very niche competitive scene, it's probably not just a difference of opinions between us, is it?
Running from Brawl? Long quit?
https://www.youtube.com/watch?v=wXbSiRlH3oM
Best ICs and best MK are still at it...
https://www.youtube.com/watch?v=nPrKYGO7WeY
So were they (that's Ally if you don't click the link)... M2K quit because he stopped making money. If Apex 2015 doesn't have Brawl, then I know that this was really the last gasp, but I heard Apex has it scheduled (though I haven't done reading to see if that's true), so I think Brawl will persist, at least in a few majors once in a while, even if it's a side event.
Also:
https://www.youtube.com/watch?v=kaUA94uVoko [there may be more recent, this was just a single youtube search]. And this is like 4 days old or whatever:
https://www.youtube.com/watch?v=0g2HP1xa--A
I think the tournament ruleset thing wasn't fully interest-based, but at least partly Melee players whining that Brawl sets ran longer than Melee sets so the Melee-biased TOs told Brawl tournaments when they wouldn't run the events seperately to shorten it or be cut. So an alternate ruleset came out, but as the above shows, people still use the normal ruleset in big events.
Tripping wasn't great design choice, but it's rarely (never) been the sole cause of a grand finals loss - other errors elsewhere lead to it (if you find me a video of someone who bops ICs but trips into their CGs 9 times, I'll take my words back - otherwise someone could ALWAYS play better). It may have been one factor leading to a stock loss at a bad time, but to say it has caused the loss on its own is simply wrong.
As for chaingrabbing, it boils down to 4 characters - ICs (who could do it in Melee too, so that's a game flaw in Melee as well), Dedede (the worst offender probably, with a 20-30% CG at any percent, but it was no infinite, except on a few characters who could remap their D-pads to avoid the infinite thanks to his terribly slow pummel required to do the infinite until extremely high percents - it sort of wrote his MU chart for him actually), Falco (whose CG was a boon but it didn't zero-death anyone except a Wolf with bad DI or if you couldn't meteor cancel - his lasers were a bigger problem for many than his CG, and he himself suffers from CGs), and Pikachu (who has very percent-specific ones like Falco, and whose infinites are mostly irrelevant, safe as another counter to Wolf since his MU against ICs isn't terrible, unlike most others who are CG'd by Pikachu). Grab releases were also kind of silly, but they either worked on MK (yay?), worked on Wario (very potent character, and this only truly affects one or two of his MU), and Lucas and Ness (who are defined by them - though Ness sucked in Melee too and still comparatively got better in Brawl). Sure Melee didn't have as many of them, but Melee had Sheik, which is Dedede who is fast. And not solidly beat down by a variety of characters, unlike Dedede, meaning you have a decent variety of advantageous secondary options for Dedede, but not so much for Sheik.
Fox and Falco outclass the entire Melee cast, and only Samus and Marth can truly run even with them - everyone else has to fight a losing MU, just like MK in Brawl with Pikachu and arguably a few flat stages + a few select characters. But in Melee you need to ban 3 characters to avoid a character with no losing MUs (Fox, Falco, and Jigglypuff since Fox is banned), while in Brawl banning MK gives every single character leftover a losing MU.
Melee had crouch-cancelling, which made some characters horribly invalid and made several moves unsafe on hit. People complain about Ganondorf dair being unsafe on hit, and I know Ripple (top PM player, got like 7th at TBH4) has said no move should be unsafe on hit, ever (I'll go find the thread if need be). Crouch-cancelling makes moves (like Marth side+B, various ftilts, everything named Roy) unsafe on hit.
It also had L-cancelling, a design choice originally made by the dev team to make shielding after an aerial occur faster. However, hitting shield triggers while getting close to the ground is a prerequisite for high-level Melee play, and it adds nothing to the game - there is never a time you shouldn't L-cancel, and it could have been entirely subverted by simply halving landing lag and removing the mechanic.
Dash-dancing is also a toxic mechanic - I know a top Melee player in our area quit because moving didn't have commitment - he finds pretty much every other fighting game more fun (and now is rapidly improving in Street Fighter, although he admits he has a long way to go) because in every game except Melee (and 64, and in some ways Smash 4 actually), moving is a commitment - you have to think when you move. There is no commitment to wiggling the control stick back and forth while waiting for a getup attack from someone on the ledge with no options - and while you can crowd someone in a fighting game without getup attacks, getups are 100% safe, which isn't the case in Melee.
Fox (and Falco, and a few other characters) also fundamentally invalidate the rock-paper-scissor nature of attack/shield/grab that is fundamental to pretty much every other fighting game (and Brawl and Smash 4). Fox can literally just keep using shine (rock) to actually beat paper (shield), which makes shielding a bad option at all times against Fox in many matchups, contributing to his ridiculous matchup spread and invalidating characters with poor OoS options (Link and G&W come to mind).
All that said, I still love Melee (and for what its worth, the DDing argument is one I've read elsewhere, and what I can remember from it - I think there were nuances I'm missing) [and also, I kind of like DDing, but I think overall movement should have slightly more commitment than it does in Melee, especially when you also can wavedash out of a dash and therefore only ever be 10 frames away from standing still - maybe one of them is good but two is probably too much in my opinion]. And the statement "It's a deeply flawed game" is still an opinion, regardless of how many people hold that opinion, and it's one I disagree with [kind of like how in the 1950s, tons of people, including many top people in the US (Congress, etc.) stated that "black people are inferior to white people." Tons of people believed it and acted as though it was a fact, but I disagree with this statement - someone could've said it was more than a difference of opinion back then too, and they'd have been wrong then as well]. I can start throwing dictionaries around in here if need be, but most people don't seem to like that.
I can't tell if you're referencing Zero or M2K, but Zero outclasses M2K in PM, Brawl, and probably Smash 4 by now, while still being high-level in Melee. And I think you're referencing M2K. I don't think M2K is the overall top Smash player. Another difference of opinion.