Wow you guys STILL have not figured it out? SEGA has tried new concepts for Sonic which have failed in many ways causing the games to suck along with lazy programming such as controls and glitches. Simple as that.
I think they suck because they just tried to convert Sonic from a 2D game into a 3D game, and didn't really think much beyond that. The original concept just doesn't work in a 3D form.