MMA is a keenly American phenomenon. veen's basic point is that American sports tend to more violence - in the rules - than sports in the rest of the world. Hockey players, worldwide (green = lots): https://vignette.wikia.nocookie.net/icehockey/images/c/c9/Hockey_Map.PNG MMA advertising by country: Meanwhile, you've triangulated to "rugby is not totally clean" which, c'mon. It's considered the most violent sport in the world by most people. You're a long way from "lol bullshit" son.
Bullriding and NASCAR were also mentioned in that piece for similar reasons. A good friend of mine plays ice hockey and sometimes gets in a bit of a brawl, but it is a sport only marginally more popular than Quidditch here and most of the brawls are consensual (as in, it only escalates if both parties want to escalate).
God, fucking NASCAR. "Let's take an 8 liter V8 and then give it stenosis so people can't kill each other." "Then let's make them go around and around in a goddamn circle for two hours and bump into each other." Fucking NASCAR. I mean, Formula 1 is stupid. But nothing is as NASCAR stupid as NASCAR.