What is even more odd is that I'm to believe the Colors team developed this one, right? they had maybe 3 years if that was the case, but then again this seems to fall into what has been kind of a constant issue with modern Sonic Team (as you mentioned "if it ain't broken" along side throwing things and hoping it's sticks idea.)
I remember reading once that Rivals was going to be platformer, until Iizuka suggested(?) to Backbone the change to racing.
I wonder how much control he exterts to the teams now that he is the head of the group, and with cases like Sonic 4/Rivals if the issues falls on him/Sonic Team/Dimps for the design and mechanic choices made. With Colors and Generations in comparison to Unleashed (which I did like fyi) and (presumably since I've only played the demo) Lost World, to even Sonic 06, it seems like Sonic Team always tries add too much variety to the pot and it doesn't work or buckles under the weight...when they should (obviously) limit themselves a bit with proper planning/focus on what works and move forward with that and maybe make improvements. I'm also curious if SEGA's release schedule doesn't also factor in.
If I had to pick someone else as a head/face of Sonic Team, I personally think Yojiro Ogawa is a good candidate. In past interviews, he seemed to have a good head on his shoulders and at least had some interesting ideas...though according to SEGA Retro, it looks like he is in Ryu Ga Gotoku Studios now.
Stranger things have happened, though really we just need someone who is consistent, it would help.