The problem is that most people think Harmonix is trying to get a free pass, getting the resources from the fans to develop a game without the risk of any failure. The fact of the matter is that, while Amplitude received much critical acclaim and an extremely dedicated fanbase, it wasn't a commercial success in the long run. Funding a game isn't cheap, and if it's something that the public isn't interested in, it's pretty much the equivalent of shooting yourself in the foo...
I can't even imagine playing Knife Party's Centipede on a decked out version of Amplitude.
Man, it's gonna be a long wait...
(Yeah, I know the song might not be there in the final version, but it's a possibility)