Also there's a big difference between timing windows and having a character slide.
Not shit. They also make their respective genre of game harder. And that was my point. I can't get jack all for good scores in IIDX just because of the tight-ass timing. That makes IIDX a whole lot harder than most other rhythm games I've played for that fact alone. Having a character that has some sliding makes them harder to control, which makes their respective game harder in some ways than other platformers.
You can't just say that because rhythm games and platformers are different genres that I can't make an analogy between something that makes one genre harder and something that makes the other genre harder.
I'm not saying I like the sliding in Mario, because I certainly find it frustrating as hell sometimes. But that's always been a part of the Mario games. And besides, there's no point in bitching about the game. If you care so much about the mechanics, go hack the rom, find the physics code for sliding and modify it.