The Indy Speedway is loud, smells bad, and you're right, doesn't look like it belongs in the Magic Kingdom. When I first went on it I was pretty annoyed, because I thought it was the stupidest and slowest ride I had ever been on.
But it isn't meant to be fast or anything like that. What I remember from riding on it is being a terrible driver, being the slowest one on the track, and steering terribly. I remember laughing like crazy because I could not get that stupid car under control. And that's why the Indy Speedway is there. The wait times are always crazy and it's doubtful it'll be removed anytime in the near future.