1: They attempt to add themes that aren't in the game originally (Example: Airship in Super Mario World) They could have used that space to put game-exclusive themes!
2: The costume mushroom is only on the first Mario Bros, at least they could still use the 8-bit sprite but it would work in other games
2: The costume mushroom is only on the first Mario Bros, at least they could still use the 8-bit sprite but it would work in other games