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.Of course Punk walked out as well and unlike Lesnar, didn't have the professional courtesy to wait till he contract expired.
To say fans are polarized that he was the one to break the Undertaker's Streak at Wrestlemania is a bit of an understatement. Reasons being: he's a part-timer (bad), he's an old veteran instead of a young guy (YMMV), he's a beastly athlete and clearly Taker's physical superior (good), he's a mercenary at heart who's walked out on WWE before (bad), he's got the most potential as a fearsome heel out of anybody active today if used and booked correctly (good), he's the most legitimate fighting badass in pro wrestling history by virtue of his accomplishments in Mixed Martial Arts, a sport which Taker heavily respects (good), the moment of his victory legitimately shocked the wrestling world, something that rarely ever happens (good), the streak is so legendary that the whole question of it being broken at all is a dicey one (bad)…let's just say this is the stuff of Internet Backdraft with a whole host of reasons fanning the flames!
Though Mick Foley makes the point that, if the streak was to be broken, Lesnar was the one to do it. Mick mentions that whoever broke the streak, there would be heat on that person, but Lesnar does not give a damn what the fans think about him.
Jerkass: Brock…has developed a bit of a reputation for this behind the scenes and in real life. It's been well-docmented that he's really only in the business for the money, but he had a bit of a jerk streak even before that point too. A great example would be from during his days in OVW. Jim Cornette tells of how his then-girlfriend (now wife) had had surgery by her…sensitive regions and had asked Brock to be careful not to squeeze it when he picked her up in the air before throwing her during a match. Well, not only did Lesnar proceed to do exactly what she asked him not to do but he also spent the entire day leading up to that moment telling her that he was gonna do it. In the locker room afterwards, when Cornette got involved and Lesnar told his girlfriend "fuck you," Cornette threatened to shoot Lesnar in the face.
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.
90% of wrestling fans have been dishing this out over his ending The Streak cleanly. See Hate Dumb above for some examples.