The Rock won the belt because he is the biggest draw the WWE has (which coincides with the majority of the fans cheering and wanting him back), As long as the Rock is affiliated with the WWE on some level, they're going to vicariously live through him to get exposure. They haven't shoved the Rock's movies down our throats and it's not like the Rock even needs them to promote his movies to begin with considering he's proven that he can be successful without them. There's no way in hell the Rock is worse than Cena in every way or in any way for that matter (and I'm not even that much of a fan of the current version of the Rock in comparison to the old school Rock).
first off take away the mic from both of them and all you got left is crappy wrestlers, without his "pg-13" mouth Rock is boring and useless, WWE has to bend their own rules because they know without profanity Rock has nothing to offer (except his celebrity status) otherwise he would have conformed to the PG rating like Cena and everyone else had to,
Cena can do "attitude" and do it pretty well from what I remember, but that's not the product now, he has adapted to the new order, if WWE goes back to the edgier stuff I'm sure we will see a different Cena, Rock has been the same one trick pony so I stand by my statement