He's moved on.
Every time an opportunity arises that's lucrative for Punk to come back to wrestling, he immediately shoots it down....and then he does it again...and about a hundred more times after that, because people keep asking if/when is he coming back to wrestling. He isn't. I can't speak for the man on a personal level, but he's been very open about his passion for wrestling being dead and buried. He's moved on to MMA commentary, reality TV competition hosting, writing, acting, and a myriad of other professional projects that seem to be just as big a part of his boyhood dream as wrestling was. I'm convinced that after telling every single person whose asked that he's done with wrestling, that he's done with wrestling.