Punk is making a statement by walking out on a near 7 figure payday, WWE don't listen to the fans, book on bias and treat the guys who work their ass off like ****, someone actually showing he doesn't need them and walking out on their biggest spectacle was the moment to do it in order to make a point and it's a point that has been well publicized due to the timing.
And that's the other thing. WWE apparently hasn't explained to their talents how the WWE Network featuring Wrestlemania XXX will impact the bonuses they normally receive.
I won't argue that the way Punk left was unprofessional. It could've been done differently. But it's like I had said, it's hard to not understand since it's something most people have felt before in their jobs, including myself.
Also, while him having a long historical reign is good to have on paper, if you look back, he only headlined a few of the shows despite being WWE Champion. That was one of the problems in Punk's mind likely: He's champion, but not the man. John Cena was still the focus. Think about it:
Royal Rumble 2012: obviously the match is the show closer here, no problem with that.
Elimination Chamber 2012 Headliner: Cena vs Kane in an Ambulance match. The Elimination Chamber match for WWE title was the show's opening match!
Wrestlemania 28 Headliner: Rock vs Cena. Understandable here
Extreme Rules 2012 Headliner: Cena vs Brock. Understandable here.
Over the Limit 2012 Headliner: John Cena vs John Laurinaitis. Yes, this was the headlining main-event, not the WWE title match between Punk and Bryan.
No Way Out 2012 Headliner: Cena vs Big Show in a steel cage. Not the triple-threat for the WWE title match.
WWE Money in the Bank 2012 Headliner: RAW's Money in the Bank match, which featured John Cena. The title match wasn't.
And the rest of the year, the title match was the headliner because A) Rock made an appearance and said he was going to challenge the champion at the Royal Rumble, so automatically they had to make the belt important again. B) Cena challenged for the belt in the next several PPVs, and they were trying to push Ryback.
So yes, Punk had that great historic reign but he wasn't the central focus. It was still John Cena, despite Punk having the belt.
And then 2013, he lost to the Rock twice, lost to Cena on RAW, lost to the Undertaker, lost MITB and then lost to Brock. So every high profile match he had he lost. His match with Jericho he won but I wouldn't consider it high profile, IMO. And then he faced Ryback and Axel, the Wyatts and the Shield. Ryback and Axel are boring midcarders. The Wyatts and Shield are midcarders as well.
So it did feel like he was shunted back down after his reign. It was almost as if they Jericho'd him. Remember after Jericho lost the Undisputed title, he went on a PPV match losing streak that lasted until September? Jericho took that in stride, but obviously Punk isn't that type of guy.
And then whatever arguments on creative's decisions and their use of talent. It's just hard to say he comes across as a baby here. Unprofessional? I'll agree with that. Disrespectful? Probably, but he probably felt disrespected as well.