Considering how the Water stage of PS1 got *****, I'd play PS2 over PS1 anyday, and of course the gimp ledge, it gets me ALL the time.
I don't ever see someone really CP PS1 ever.
The worst thing about PS2 is the Wind part, you can sorta' camp it out a bit, depending on who you are, but that's sort of the point of a CP.
There isn't really a reason to ban either of the Pokemon Stadiums.
As mentioned earlier, Norfair, Pirateship and Rainbow Cruise, why should they be banned?
Norfair: People always complain about free damage inside of the capsule and stuff. Don't go in it. Shield the lava, air dodge it, edge camp to avoid it, it's easy to avoid. There is nothing to really break this course AT ALL.
Pirate Ship: The only thing I could argue against this is a temp infinite against the catapult when it's out, but that's only for a couple seconds if anything. The stage hazards are avoidable, and not much else to break it, and further make the game unplayable.
Rainbow Cruise: There's a wall like one time throughout the route, and then the boat wall, but in turn, those are temp. Saying you should ban it for that is like saying you should ban Delfino cause it has walls for a section. Nothing else to break this course.
Mario Circuit and Green Hill Zone are banned because the walks off, that's a huge factor, that would make a match way too one sided, so saying you don't understand why those are banned, and why the three above are, you have to understand the qualifications a stage has to have in order to have it be banned.