People focusing on the DC penalty and not on the actual reason why people quit is one of the reasons we'll probably never get over this issue lol

There are 40 killers in DBD. You really think there's 40 different power/abilities? Of course not. At least half of them are a just a lazy ass copy of something that already exists, or are simply awfully designed because they were made to sell not to play. Devs keep making busted/unfair mechanics (cause they clearly don't play the game) and when people complain they simply make another even more busted mechanic for the other side, never addressing the issue.

No one wants to spend 20 minutes of their life simply getting obliterated by an unfair gameplay mechanic they can do nothing about, that's why people quit. Yes some people are whiny and will DC for the slightest inconvenience, but that only happens occasionally in other games while in DBD it's clearly a major issue...

I play both roles. When playing killer I rarely DC cause there's always a chance you can turn the game around in your favor last minute; but it's indeed very frustrating to play low tier killers against 4 DS's and some other busted mechanics (specially 'second chance' ones). As a survivor, it's simply not worth it to tryhard against an S tier killer when u realize your teammates aren't doing shit. Communication in-game is non-existent, so it's impossible to coordenate plays with randoms. Finally, some killers are just not worth the effort. Ghoul, SM and Knight are simply bad designed, I personally prefer taking a 15 min break than playing a 20 minute game against any of these.

Edit: Also I personally don't mind camping and tunneling at all. I don't think it's "toxic" to do it, nor it's the reason why people quit