My view:
The "RESTART" option is - in fact - a "REWIND" option. The only difference lies in the length of the "go back in time" feature. A "rewind" let's you choose, a "restart" doesn't, you are rewinded all the way back to the grid.
In my opinion, any "rewind" or "restart" feature that allows a player to avoid messing up their oh-so-prized game stats (win-lose ratio is one of them) is arcadish. You made a mistake, live with it if you are so "serious" about playing a "sim"
Online playing doesn't have "restarts" (and of course their shorter version, the "rewinds") and it can be frustrating at times, but that's where you'll find the "real thing".
So, I have nothing against that feature being available in the game. And I bet all players in the world, even those that say "NO", will use it if it's there.
Much, much worse, bordering a total joke, was B-Spec Bob in GT4. That was the console playing for you (but again, I don't mind it being there, I'm not forced to use it).