Wow, so glad to see someone else experiences this!
Like, I will swap my lane pre-game, cuz Precious doesn't want to play ADC and prefers Jungle, even though I'm jungle main. But whatever you know it's just a game, sure I'll switch... even though I tell them ADC is my worst role.
Then the top laner dies under enemy tower, blames JG, so I just tell the Top to stop over extending if they want a jungle gank, backing the Jungler.
Then 2 minutes later the jungler will gank my bot lane at a really bad time, dives enemy under tower and gives them a kill, which is somehow my fault and I am trash and worthless and should uninstall. After everything.
The bottom line is that people can be stupid in multitudinous and complex ways. It can be a mixture of ego and ignorance, for example - a dangerous combination. You also have to remind yourself that a lot of kids in this world aren't raised with decent manners/given decent upbringings, and simply have not learnt to have decorum, empathy, or the value of being a kind person.
League is basically full of insolent little shits.