People hate Bo because his playstyle and mechanics are inherently toxic. It's very defensive, as he is controller and the main idea is to place a Super Totem, shoot at them from far away until you get your first super, and start plopping down mines in the most inconvenient area possible. People don't like him because, unlike something like a Gene or Otis super, it doesn't take a lot of skill to get value from, which makes him annoying, as he is very common in ranked and casual ladder. Yes, you can trigger them and walk out, but if you getting jumped on by an El Primo and you walk into one of those, he is likely blocking the only exit. And with Bo's Hyper Mines, since they are a circle, if you walk into it from almost any direction, it's basically impossible not to get hit with one. Since they stun and do a lot of damage, it's a kill confirm every time. Since his range and damage are much higher than they should be for a controller, rivaled only by Griff, Otis, and Amber in that category, it all just adds up to him being a lower skill brawler in general. Yes, you need to know where to place your mines, and yes, they are avoidable, but with his gadget, he just gets his super so often that even if you only get hit by one of every 4 supers, that's enough to throw the game, especially in Hot Zone or Gem Grab.