I think the opposite, actually. Most people do know the rules, their understanding of them is just very poor. You'd be surprised how many people come here with chat logs saying things like this (quoted below) aren't toxic and that we're a bunch of SJWs.
xXxMeMeLoRDX69: trist trash lol
xXxMeMeLoRDX69: dude just uninstall
xXxMeMeLoRDX69: this team lmao
xXxMeMeLoRDX69: report trist please toxic troll
xXxMeMeLoRDX69: can't carry this
xXxMeMeLoRDX69: you guys are throwing, where the fuck is your damage
xXxMeMeLoRDX69: jesus fucking christ this rengar is a pussy
xXxMeMeLoRDX69: enemy jungler won't get the fuck out of my lane
(obviously made up just for this comment mods pls don't remove this)
I wish I was exaggerating, too. These are pretty much your average 'Player Behavior' posts, titled something like "Unbanned fairly, proof inside" or "Riot's system is bullshit, I got banned for THIS?"
I've been permabanned before, I know what it's like. Most sane people are able to understand what will get you punished after a 10/25 game chat restriction. It's just some people in the community don't listen and they need to be punished accordingly. IMO it's just a matter of people being bull headed.