Why is selecting "so-and-so" such a big deal to people?
And by "so-and-so" I mean champions such as:

That's all I can think of for now as of champions, I find this kind of an issue for myself when I sometimes solo queue, especially with low elo players
When I play champions such as Yorick, Urgot, I get bashed on by my team like: "Wow, we're gonna lose cause this ****** chose _____. gg"
I don't see what the big deal is for choosing certain champions people like playing.
I'm guessing there's always people thinking that if you choose:
etc. they consider themselves gods in the game.
Does this happen to anyone else for choosing underplayed and/or underrated champs?
Had to get this out of my head.