In June of last year, CM Punk was setting the WWE on fire, and wrestling fans were frenzied; not since the glory days of Stone Cold and The Rock had they genuinely supported a character to such an extent.
It is unclear if the reports of CM Punk's expiring contract were legitimate or part of an elaborate work (the latter most likely), but one observation is crystal clear to most fans today: Punk was wildly entertaining during the buildup to last year's Money in the Bank pay-per-view, but not so much afterwards.
During the time when fans were led to believe Punk was legitimately leaving WWE, his promos were absolutely scorching and conveyed precisely the burning opinions of legions of diehard wrestling fans.
At the time, Punk was speaking as Phil Brooks, not the WWE character we see on television today. His verbal tirade against Vince McMahon while both were in the ring negotiating a new contract is a creative high point during this timeframe.
As Punk claimed, he had indeed made pro wrestling socially relevant again. Fans around the world wanted more from Punk week in, week out.
He went on to win the WWE Championship and then left the company. Most fans knew he would be back at some point, but when he did reappear at the end of Raw a few weeks later, he was somehow...different.

7:52-13:44 = MONEY
Sporting new theme music and a new t-shirt, Punk returned much more pacified, as if his character had been censored quite a bit since first cutting his epic promo.
Punk fell in line, and the marketing machine began working again.
He began speaking as a character very much entrenched in the fiction of WWE rather than as an ambassador bringing to light the very real complaints of wrestling fans everywhere. 
We no longer heard the voice of the voiceless.
We only heard the voice of CM Punk.
When Punk began his crusade against WWE, it was the major storyline on the show. Every other storyline seemed insignificant compared to the real issues he was presenting, about which fans truly cared.
After Punk's return, the fiction continued. The character cooled, and the status quo recovered. Essentially, the voice that initially made fans listen was suddenly gone, long before any of us were ready for it to go.
Like a politician during a lengthy campaign, CM Punk made us believe that change was coming to WWE; that those in charge would be forced to rectify their mistakes and change their ways.
Things were genuinely going to get better.
Then, unfortunately, Punk was elected, and all the promises were broken.

P.S. Where are my WWE ice cream bars?