Aight, here's my opinion about mute city being banned, take it how you will.
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The way I see it, they're justified in banning mute, but at the same time it's unfair.
They're justified because unless a miracle happens, it's a stage that peach, jiggs, and samus WILL win on. That's a fact. The stage is made for them and everybody knows it. They dont need ledges to recovery and this is a 20 year old fact for an 8 year old game.
But the big thing is it really is unfair to take it away from you guys (moreso you guys (Peaches) and Samus). It's one of the few stages where you ALWAYS have a clear cut advantage over the other character (unless they play one of the 3 characters.) Now yes, but logic of why stages were normally banned, that actually does constitute mute city being banned, "If you're not playing one of those 3 characters, you're at a huge natural disadvantage", but at the same time, I DONT SEE WHY THE **** PEOPLE DONT JUST BAN MUTE AGAINST YOU PEOPLE ANYWAY. It's not like it's netural, so it's SUPPOSED to be kinda unfair for one side (although again, I will admit that it is extreme in your case) I mean realistically, no other stages gives you people (specifically peach/jiggs for this one) an unfair advantage. Yes, you get an advantage on brinstar, but it's nowhere near as bad as mute city. Heck, Mute city being bad really comes down to specific matchups, cause I'd image some characters would rather fight you on mute city than brinstar.
Realistically, look at how many people dont ban mute city against Armada and Hbox, and look what usually happens to those people in a set.
In the end, both sides of this arguement are justified. Just chalk it up as a learning experience if you're a person who kinda depends on Mute City. (I mean ****, Ima doc main and I'm kinda shaking at the fact I wont have it.)
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You've got other stages, you'll just have to CP against player habits instead of CPing character abilities.