Part of the problem is that those things can happen on normally acceptable stages. Smashville for example has no problems besides really helping out Wario time out people, and helping MK scrooge. Even on starter stages you have stalling/near stalling issues. The stage list, with all stages that had problems like that removed, would be incredibly small. You might have a stage list of under 5 stages, including CP's. Most people can't live with that, so here we have starters and CP's with these problems legal.
Some of it is blatantly obvious, and IDK why the stages aren't removed by now. Brinstar for example is gross for both "regular" timing out and strategies like sharking or planking opportunely where you don't need to grab the edge as much to stay safe because of how the stage works. As much as I love stages like that, I don't see how in the world we can allow it if we also allow those things to happen freely.
Then you have stages which are quite gay and have issues, but most people have a hard time visualizing them. Japes, Green Greens, and Norfair for example. Most people don't see the problems with clustered multi edges, safety under the stage, platforms or stage gaps forcing people to jump/be airborne to get over there which allows you to outmaneuver them with a faster character, etc. I don't completely blame people for not seeing this, or not believing it until it happens set after set. Most people see non gay sets on most stages anyways, we're not conditioned to expect the gayest all the time even when it comes to MK.
Yes there is something wrong with the stage list. Our CP list is probably too long sometimes, and our starter lists can include stages that have no place as being starters. Delfino for example is in no way starter material unless you use so many stages that eventually you have to include it. Even then, there are probably better alternatives to it. 9 stage starter list for example should probably include Frigate over Delfino. MK on Delfino is Lol, there is no comparable for Frigate. Most people though say "Well that's just MK" and include Delfino because they think it balances out ground and air stages when in reality it probably shouldn't be a stage anyone with a gay mindset should start out on.
Our stage list, a lot of times, seems collaborated on based on the notion that people won't play gay, or THAT gay, or that often, etc. Sure, Brinstar can be gay, but how many people will abuse it? Not that many? Ok add it in. Stuff like that. Oh Delfino is gay, how many times will the first game be played out there? Not that many cause you can strike it? Ok add it in Lolz.
There's also a problem with MK, even if you think he needs to stay. He's too powerful when left alone. No LGL or stalling rule encompassing planking well means that he is auto win against everyone (Even after posting the Frame Data and going over a ton of Hitbox stuff with some people, everyone seems to have the mentality of "Well I'll believe it when I see it"). As bad and arbitrary as LGL can seem, having that around is better than "LOL HERE YA GO MK COOKIE FOR YOU, NOW GO ****".
If we want MK in the game, and make him not a problem, make the stage list more conservative. "But I love Brinstar, now Peach can take Diddy or Falco there and win!" "Oh well sure diversity would be nice, if MK wouldn't come along and IDK, say Shark and time you out with no good response to it from the entire cast. Yay for auto win stages for the best character in the game already?" That's the problem with expanding the stage list. You can get diversity of character usage (In a NON-GAY world where not everyone picks MK and plays gay), at the expense of making MK grow in power. If you want MK to stay in the game, please at least don't cater the stage list to him. I'd rather play on FD all day with MK allowed than watch more of this nonsense of him elsewhere.
Fix MK, Fix stages, or Fix both. Either way, both of them have problems.