why so rude?

i rarely talk in game. I'm also not plat. not even gonna say I'm gold. I'm unranked and playing my placements. OK I'm not doing good but before i even die once i get flamed. I've reported them all. every flamer I've encountered but i haven't seen one notice from riot games letting me know anything happened. but i digress. my point is why for the last 5 games in a row have i been flamed and why does the community think this is acceptable? many of you will say, well we aren't like that, or that's a small minority. but if it is then why does it seem to be a reoccurring issue? more importantly why do people think that its OK to be rude to your own teammate? I'm well aware that this issue has been present since 2009, but I don't think the way Riot is tackling this issue is effective in the slightest.

tl;dr play any champ and gets flamed, every game whether I'm doing good or not. on the verge of quitting due to toxicity.