Unless Cena was involved in the match, Punk (as WWE Champion) hasn't main evented a PPV since TLC 2011, and only once in 2011 without Cena before that...it's all been Cena, Cena, Cena, Cena, and more fucking Cena, with a bit of Triple H ego massaging thrown in. Here's a rundown of PPV main events since Punk's win against Cena at MITB last year...
Money In The Bank 2011 -
John Cena vs CM Punk
Summerslam 2011 -
John Cena vs CM Punk
Night Of Champions -
Triple H vs CM Punk (No DQ match, won by the momentum killer Triple H

...also worth noting that
John Cena won the WWE Championship in the match just before it)
Hell In A Cell 2011 -
John Cena vs CM Punk vs Alberto Del Rio Triple Threat Cell Match.
Vengeance 2011 -
John Cena vs Alberto Del Rio Last Man Standing match
Survivor Series 2011 -
John Cena & The Rock vs Awesome Truth
TLC 2011 - CM Punk vs The Miz vs Alberto Del Rio TLC Match
Royal Rumble 2012 - Royal Rumble Match (Surprisingly, neither
John Cena nor
Triple H were in the actual Royal Rumble Match. But as WWE Champion, neither was CM Punk)
Elimination Chamber 2012 -
John Cena vs Kane Amubulance Match
Wrestlemania 2012 -
John Cena vs The Rock ('Once in a lifetime!'

)
Extreme Rules 2012 -
John Cena vs Brock Lesnar
Over The Limit 2012 -
John Cena vs John Laurinaitis
No Way Out 2012 -
John Cena vs Big Show (Steel Cage Match)
Money In The Bank 2012 - Raw Money In The Bank Ladder Match (featuring, and won by
John Cena)
Summerslam 2012 -
Triple H vs Brock Lesnar
Then after that...
Night Of Champions 2012 -
John Cena vs CM Punk
and (as we all already know), the only reason he wasn't in the Hell In A Cell main event was because of his injury. As the WWE champion, Punk's only main evented 1 PPV without Cena being in the match, and only 2 when Cena
was in the match (Summerslam 2011, Night Of Champions 2012). Really unfair to say he's been responsible for any lower buyrates asides from (maybe) TLC 2011.
