Totally unobjectionable, nothing of substance at all, any disagreements are
objectively wrong? Regardless of whether or not you agree with them, you can't deny that there are some complaints to be made:
Delfino:
Just look at this silliness and tell me there's nothing I'm allowed to object to.
Kongo Jungle 64: Well, it was banned in Melee for easy camping as some characters can't reach the top very easily. Now that may or may not be a problem again, might as well test it to find out, but it's possible. Just making a note of it. I could see it being unplayable for Little Mac.
Skyloft: Temporary walkoffs and walls. You can argue that temporary makes them fine, and I'm not gonna rehash that whole argument for the dozenth time, but you should at least be able to acknowledge that there is an argument to be had here. Also, 15 seconds per transformation, air and ground, is very fast and sudden, has you moving around too much.
Halberd: Uh, a bigass cannon sniping at you the whole time?
Castle Siege: On the flipside from Skyloft, a walkoff that lasts an entire 40 seconds + load times (does it still load midmatch like in Brawl?). Now that's too long.
Wuhu Island: See Skyloft, plus swimming.
Windy Hill: Weird gravity changes how geometry works. Things are essentially farther apart higher up. This can throw off some combos, followups, and setups. Also, some projectiles don't follow the curvature, like Thoron. Having a stage that changes entire game mechanics and disrupts physics is really bad IMO.
Also, wasn't Pilotwings more or less declared dead after it became clear how easy it was to stall?
I apologize in advance for what I'm about to do to this post. I think basically eveyrthing said here isn't reasonable, and I said "objectively unreasonable" to characterize opposition and not "objectively wrong". Unreasonable and wrong are different words that mean very different things...
I see nothing objectionable there. That gif of Delfino isn't even 4 which makes it dubious in the first place, but just ignoring that since the same mechanics exist here anyway, what's unreasonable about that situation? A MK player is off-stage and gets hit by a meteor. This leads to his death. That's pretty much the same dynamic that exists on every stage. Water is like the least ban-worthy thing ever. The only argument I heard for banning this stage in Brawl that made any sense involved MK playing under the stage which was kinda a problem on every stage because you know MK in Brawl but was worse here, but this is a very different engine in which that tactic would not be very successful.
Stalling on Kongo 64 really doesn't work. Not only did it only even kinda work in Melee in a small number of match-ups (and even there it really wasn't ban-worthy; I really am against that ban and I think a lot of Melee players agree), but the stage is smaller in 4 with generally different physics and character dynamics that STRONGLY weaken such a tactic. It might be bad for Little Mac, but Little Mac is a kinda bad character so a lot of stuff is bad for him. I've played a ton on this stage in 4, and it plays really, really well.
What do walls do in 4? They don't do anything as far as I can tell. What unfair advantage can you get from a temporary walk-off? What tactics can you pursue that will give you an unjust advantage or even really prove problematic? Saying it's ban-worthy really isn't reasonable because I don't think a reasonable position has ever been presented on the topic. You don't even really have to move that much; the floor comes under you with each transformation. The geography changes around you; you don't have to keep up. I actually think Skyloft is the #1 best competitive stage in 4; it's just a god-tier stage with nothing wrong with it at all, and it's absolutely critical to have this stage as legal as legal can be since it adds so much to the game.
Halberd's cannon doesn't snipe at you the whole time; it only can attack when you're on the deck of the ship. All of Halberd's hazards are absurdly slow and predictable to the point that it's just trivial for a good player to avoid them (honestly at most tournaments, even the very worst player present is good enough to avoid Halberd hazards; it's that easy). This is easy to avoid to the point that even an opponent actively trying to force you into them will rarely succeed. They don't come very often, and honestly they're pretty tactical in how they affect the neutral when they come out. This is a great stage, and it was commonly legal in Brawl for good reason (with the main problem, MK playing under the stage, being fixed).
I honestly find the question about mid-match loading telling on Siege. Do you not know? Are you arguing a ban is reasonable while not knowing the stage's mechanics? The transition form still exists but is very brief in 4; it does not seem like the stage is loading mid-match (and the situations in which that mattered in Brawl, transforming characters being blocked by stage load, don't exist in 4 anyway). The lips on ledges are also gone now which removes a common annoyance of this stage, and the general changes to character mobility and attack patterns make stalling out the second form harder. Castle Siege was already a good stage in Brawl commonly legal in tournament, and it's non-trivially better in 4.
Skyloft and swimming are both without flaw so Wuhu is great? Wuhu is actually a really interesting stage that IMO has pretty strongly different match-up implications than Skyloft; after Skyloft, it's IMO the second best competitive stage in the game just for how much it adds to the game for being present.
Windy Hill's gravity effect is very weak, and it's not weird. It's just... gravity. I toyed with it quite a bit (and have played some games here to put it in practice), and it is not only very intuitive but not even very important. Massive objects behave under the effects of a gravitational field and fall toward the center of gravity while massless objects are not significantly acted upon by gravity over ordinary area scales. That's just ordinary physics at work, and while that effect isn't represented on most other stages, it should be very intuitive to anyone who grew up on a planet with a curved surface which I believe is all of us. Beyond being intuitive, it barely matters. Doing direct physical attacks on a curved surface versus a flat one is exactly the same thing. All of the same set-ups and combos work here that work everywhere else. You have to think a little bit more about projectiles, but when you remember to just think of it like how gravity actually works, it's very easy to wrap your head around. It's also worth noting that projectile zoning is substantially different on every stage versus any other just because of the way it's super dependent on geography. Like this stage I feel is litmus-test style in that it's just so eminently reasonable once you play on it a bit but seems dubious if you just look at it and don't confirm through play (in particular it looks WAY bigger than it actually is; matches don't go slowly here at all). Honestly this stage is really, really good itself, and I think it has an important role to play rounding out the stage list (it works like an inverse Kongo in a few ways, as weird as that probably sounds).
I'm not in the business of defending Pilotwings. I think the stage is marginal, deserving of significantly more play before being written off but not a top candidate.
So yeah, I actually do really believe in all of these stages very strongly. I've played on all of them enough to be sure; they're legit stages. Like I said, I'm not supporting 13 legal and that's it (I like quite a few more!), but 13 is an easy number to strike from (it's not slow at all guys; just try it seriously, and also stop agreeing to Smashville it's not to your best interest I always strike that stage and get one I like more) and those stages are just so unobjectionable and have such top quality gameplay. This game has very, very good stages, but you have to actually play on the stages to appreciate how good they are...