There are more than just the elevators that are curved. The majority of them are. Transformers uses them because its trying to sell a forward motion, and a curved screen does that (see: Cinerama in the 1950s). Spiderman doesn't actually use a simulated forward motion until the end, and those two screens are curved as well - and Spiderman slows to a crawl at that point as well (the cars swivel a bit in front of the screen, using some fancy optics). Its one of those they seem similar because they use the same system and tricks, but actually the story each tells requires a different kind of cinema illusion. (Sorry but is the cinematographer nerd coming out)