I played Brawl+ with no decay, and felt that it made characters die too quickly. I personally liked that in Melee it was a common occurrence for skilled players to live up to 180-240% on a fairly regular basis. Without move decay, characters dies between 60-130% almost all the time, and while DI is powerful, the boundaries of the stages are too near the actual stage to let you live much beyond 180% in the most extreme cases.
This does not happen often in Melee at all if people know how to kill. Brawl matches take too long, and it makes it boring to see a match 2 minutes in and the first stock has just been lost.
Please, explain to me how decay doesn't help tighten up matches? A character who dies does not suffer from stale move decay, while a character who has just taken off two of his opponent's stock without dying is suffering from decay. This makes it more likely for the opponent who is behind to take a stock off. Obviously it has a rubber band effect, but it initially provides the person who fell behind a greater chance at closing the gap, and then working to keep it close. Many of the people I used to play against that went to tournies typically would manage to get ahead of me by at least one, if not two stock, but I was almost always able to make it back up in the end, and often sneak in wins, upsetting the match.
I don't know what you specifically mean by "Tighten up", but Brawl's decay just slows down matches and makes them more boring to watch/play. It's not fun to have to conserve your kill moves, it's an arbitrary limitation that is very annoying (imo)
If a character is not suffering from decay, he is just as likely to open the gap up further as he is to getting hit (ignoring counter match situations, which make no decay more harmful to the characters at disadvantage).
Helping the loser is exactly the mindset that created the abomination that is Vanilla Brawl. You should not get benefits from losing.
This was a theoretical situation. I will come out and admit I know very little of the current metagame in Brawl, I stopped playing competitively a few months after the game was released (though I spent quite a bit of time researching match ups for ZSS and was quite the avid poster then, and for Link in Melee). I'm more familiar with Melee and SSB64, and there were some very serious counter match situations in both of those games where some characters could use less than four moves and completely shut down other characters. Spam isn't the right term, but using a very selective list of moves to completely shut down specific characters is a very real problem in most fighting games.
You may think it's lame to only use "4 moves", but in reality the only reason they refrain from using other moves is because they're not good. Forcing the players to use worse moves does not make for more interesting gameplay.
One example I can think of for vBrawl off the top of my head is MK vs. Falcon. Regardless of what Falcon does, he suffers from a lack of priority, range, and too much lag on his attacks to pose any real threat to MK, who can shut him down with a few aerial attacks and his jab, or just shield most of what Falcon does and punish him afterward.
Good Job, you just took the best and worst characters in the game as an example to say that you need to limit the player.
EDIT: I will agree that it would be ideal if we could find someway to just change damage decay, as opposed to having to change both damage and knockback.
Agreed