Winning the belt in a scripted sport doesn't really mean he's still "relevant". Ratings are still pretty much no different than they've been for the last decade. If he'd come back after a ten year absence in a legit sport and won the title, it'd mean something.
Then again, I'm one of those guys who are bitter at a part-timer holding the belt, yet never even appearing on the shows for no other reason than "he has other stuff to do".
With that said, from a kayfabe point-of-view, who the fuck does the Rock think he is? Not even a contracted WWE Superstar, who is he to just waltz into a company and be all like "right, this is now the WWE Championship", and have nobody from higher up challenge this decision. Don't get me wrong, I like the new belt, but I mean this from a kayfabe perspective. I don't just go to my job and say "ok guys, from now on this is the uniform we wear", so why hasn't Vince or Triple H or something questioned this decision.
Unacceptable. The Rock is a douche.