I never truly "got" CM Punk. I think he's a pretty good wrestler but nowhere near as good as a Seth Rollins. I did enjoy his "pipe bomb"-era promos, and the whole program with Cena where Punk's contract expired with him as champion was awesome.
But in real life, he's a dick. He complains about the heat he got in WWE developmental, but conveniently forgets that most of the heat on him was due to him sleeping with most of the developmental women. If you think that's not a big deal and none of their business, think about what the morale in your office would be like if there was one guy serially sleeping with the women you work with. It wouldn't be great, that's for sure. He complains about how WWE used him, but holy crap the whole aforementioned "pipe bomb" stuff was something they let him do. They let him hold the WWE championship for over 400 days. They paid him extremely well, enough that he could up and leave and go play "UFC Fantasy Camp" (TM FreebirdSTF), and then he pissed all over them on the way out. They did all this even though he wasn't the "company guy".
As for the lawsuit, I can understand he might be upset with Cabana for going backstage, but let's be honest, he's not considering that Cabana has nowhere near the money Punk has, and probably would like to get himself out of that situation entirely rather than be bankrupted. The story that Hornswoggle noted is frankly just bizarre, and only furthers the fact that Punk is a dick to his friends as well as the people he considers his enemies.
I hope he gets his face kicked off. :-)