There is this weird environment which riot created, where negative aspects of the single player game are still given shit, but the team play aspect is very much undervalued by the community compared to riot. I do blame riot for this more than the community though. I don't think they had any way of knowing this would be what would happen, but i do think it's a side effect of them trying to fundamentally change their game. Fundamentally this is a completely different game than league of legends from 2012-2013. It looks the same and goes by the same name. 2010-2013, the game's pacing was similar to that of RTS. Where as now, the pacing is more akin to fps games, fast paced, and putting instincts over tactics.
If you do or don't engage into a situation which is different from your prospective, people give you shit for no real reason. Yes, i went in on that, because clearly i was thinking i had more damage potential than you did with your 20/20 hindsight.
The combination of team play being more influential than solo play, the snowball nature of the early game, and the old style of solo carrying makes it pretty much impossible to play well, and make the "right" decision in every situation.