I'm not sure how you can't get that I am advocating they build on what Punk brought. Not just stick with it.
It's like the people back in mid 2013 claiming "Bryan's not a draw, you can't push him!", well no shit he's not a draw, they hadn't pushed him yet. You don't become a draw overnight, and Bryan, surprise surprise, is a draw these days, who pushes ratings, attendences and merch.
Rock/Cena was all well and good for one night of buyrates and gates, but what about the next night? Rock was gone after one promo and didn't show up for six months more. Meanwhile, Punk was there the whole time, being shafted in favour of Cena every month. Had they built up Punk from the pipebomb in mid 2011, he could have been surpassing Cena by WM, bringing a much different audience than Cena brought. They never capitilised on their different appeals.
Maybe the reason WWE keeps having to rely on part timers to provide a bandaid on a ten inch laceration is because any time they get handed a new top star on a platter, they ignore it and go with Cena anyway. Punk, or Bryan, or even guys like Ryback or Ziggler who couldn't be the top guy, but sure could have been main event guys, all botched. Bryan came the closest, but they still beat him up every week and book him as weak or non-serious.
Yet then here comes Roman Reigns, who mysteriously gets the perfect top guy booking no one else did. So they do know how to do it, they just choose not to.
EDIT: 30k extra buys from ONE PROMO is something to be noticed. Imagine what a year of promos and builds could have done.