Okay so...
When The Rock originally made his return, it was fantastic. Great Rock promo where he ran down the roster and cut some fantastic lines, particularly on Cena that only he could have got away with.
Then it all just went south from there.
They needed to strike while the iron was hot, instead the WWE had to come up with a stop-gap Mania main event of Cena/Miz. Truth be told, that match shouldn't have main evented - Cena should have been involved elsewhere and they could have done the deal there.
To make matters worse, the build sucked. Nobody cared about The Miz, it was all about Cena/Rock and even then the promos always had something wrong with them. For instance, Cena comes at Rock with a good rap promo - instead of brushing it off like The Rock is known to do - he cuts this whiny defensive promo about how much he cares about the fans...in a pre-tape pomo inside his home.
The problem was, The Rock was limited in what he could do - he could only cut promos and he had to somehow keep fans interested in a match for an entire year using that one skill alone. It was a tall order, and the WWE did little to keep fans interested in other matches on the card. There wasn't a whole lot of build towards the card - Taker/HHH had a similar sort of build that came from left field and Punk/Jericho was just thrown together - the rest achieved little as well.
To make matters worse, they extended it another year after that and while the return was a touch better, it suffered from sequalitis and by that point the crowd was completely mixed on it and weren't very receptive to Cena finally overcoming The Rock - I don't think he really needed his validation to be recognised as the face of the WWE.
