That's not unique to Pokémon though, some locations that end up being stages don't really get a treatment that makes them represent the location very well. Take Fourside for example, while we have the Helicopter and the Monotoli building nothing else really hails from Fourside, it's just a random big city at night, which is also very odd since you never see Fourside at night in the games, Moonside would be the closest to that. The UFO is very random too, since it only actually appears in the game's opening title card. Then there's some kind of construction going on, and Fourside is never under construction in Earthbound, so I don't know where they got that from.
Then take Brinstar too, this one was really messed up. The platform you fight on doesn't have the tiles of colors of Brinstar at all, Brinstar has had blue, green and red tiles, but never mucky barf colored tiles. Then there's the acid, which was only present in the original Metroid and wasn't present at all in Super Metroid, and it wasn't a very frequent sight in the original Metroid to see acid in Brinstar either. And then there's of course the brain thing in the background, which never appears in a single Metroid game. The only brain ever present in the Metroid games is Mother Brain, and that thing in the background of the stage sure isn't Mother Brain. I guess you could consider the Aurora Units brains too, but they debuted in Metroid Prime 3 and have never been on Zebes either. The Brinstar stage is a disgrace to the actual location if you ask me, because there's nigh to nothing unique to Brinstar that is in that stage. The only thing that actually makes Norfair acceptable in Brawl is the background of the stage which is obviously inspired by Norfair, but I'm kind of ticked off at the actual platforms you fight on, since Norfair doesn't really have metal anywhere other than the way to the Ice Beam in Super Metroid.
Of course locations have to be altered to fit properly in a fighting game, I think they transitioned Spear Pillar and Saffron City well in that regard, but when there's little or absolutely nothing that points toward the stage actually being based off of the proposed location, like with Fourside and Brinstar, then it's just plain annoying. I understand that they can't pack every stage with references like with New Pork City and Halberd, but instead of adding a random brain they could at least add something that makes sense instead. For the most part I think Sakurai does it well, but sometimes... ugh...
