This is a team game, right?

So I joined LoL in S2 I believe and have been having fun... even though I mostly play bot matches for some reasons. Even though my understanding is that LoL is a team game, a lot of the time I find myself questioning if it really is a "team game". I mean sure we have the pro teams and we have the teams trying to clime up the ladder but besides that... aren't following? Well a lot of the time my unranked games go like this, enter champion select, and right off the bat people start yelling at other for (A) the champion they picked or (B) not letting them be _______ lane. Enter game and people most of the time (A) won't listen to what other people say (B) yell at the team and say they all suck whenever they die, no matter whose fault it is (C) AFK for no reason or because the team is "A bunch of n0obs who can't play the game and should get off lol now" or (D) all of the above and more.
And here I am trying to figure out how to get better but it gets really hard when over half of the team…
And here I am trying to figure out how to get better but it gets really hard when over half of the team…