the Rock's decisions have to do more with his distaste for Vince and nothing to do with the Fans he adores so much.
Vince is a piece of shit.
That shit doesn't make any sense. Rock don't have to be nobody's bitch. Doesn't have to sign a fucked up contract that other "legends" (mostly broke and out of work) do. None of that shit. Rock can do appearances 100% on his own terms. Hell, he'd have more negotiating power than Stone Cold, Bret Hart, any of them.
If he hated Vince that much, he could demand an extraordinary amount of money and then donate it to charity. But that motherfucker won't even do that. He turned bitch, plain and simple.