These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Base Breaker: He's...a bit of a touchy subject among wrestling fans. On one hand, it's hard to argue with the fact that he's a hell of a talent. On the other, there's a lot of resentment over the fact that during his first run, he had (in the words of CM Punk) the keys to the kingdom handed to him and just walked out.
Hate Dumb: CM Punkfangirls are starting to become this following the start of Punk and Brock's storyline together in 2013, claiming up and down that Brock is unsafe to work with because of one segment where he basically threw Punk around, even tossing him across the announce table, resulting in Punk later tweeting a photo of a bruise he received. This would sound sympathetic if not justified at first, except for how they completely ignore the fact that Lesnar manhandling Punk around was part of the planned storyline to make Lesnar look like a dominant beast, that the big-guy-tosses-little-guy-across-the-table spot was done in a match on a pay-per-view between Dolph Ziggler and Tensai to much less of a shitstorm, and that pro wrestlers get bruises sometimes as the nature of the game and treat them as battle scars to be proud of, like when Taryn Terrell recently tweeted a pic of her bruise following her Knockout ladder match with Gail Kim and almost nobody saw that as reason to bash Kim.
Narm: He's never been a strong promo worker, so they had Paul Heyman do most of the talking during his first run. They didn't get him back at first for his return, leading to this gem during his contract signing: "This is real, John. This is a real feeling that you're feeling, because I...can FEEL IT!" Brock set a record for most uses of the words "feeling" and "real" in an episode of live action television on that night.
X-Pac Heat: Brock Lesnar's background in pro wrestling is constantly mocked and decried by his detractors.
When he defeated perennial fan-favorite and UFC Hall of Famer Randy Couture the crowd was solidly against him and roundly booed him during the post-fight interview.
Then there was the infamous post-fight rant after his second bout with Frank Mir in which he attacked a major UFC sponsor and concluded with the now-immortal, "I might even get on top of my wife tonight."
He's got a bit of this in pro wrestling, too. Mainly because he's always been honest about only being in it for the money, where as most fans tend to have more respect for wrestlers who are in it because they are truly passionate about the business.