"Called it!"

One of the most aggravating aspects of playing League of Legends is being surrounded not only by idiots, which is inevitable when interacting with humans, but by idiots who still think they're in kindergarten. Granted, many of them really are children, as the game is free to play and attracts those without credit cards. This does not explain the prevalence of the following behavior.

The game has a pick order. The five players on a team are arranged from top to bottom. They pick in order from top to bottom. Regardless of what this mechanic is based on, for any individual team's purposes it is an objective means of determining who gets to pick his favorite role on the team first. Every player will sometimes land in the first or last spot.
Regardless of this, as soon as the selection pre-game timer starts, players will start spamming chat with "i'm top" or "i'm not playing support". This is the equivalent of siblings "calling shotgun" on car trips or "calling" playing the cops in cops and robbers. What's more amusing is that League of Legends is by no means full of children. The adults in the game, at the very least college-aged, have regressed to this schoolyard mentality in a remarkable example of Stockholm syndrome. The depths of stupidity reachable in this way are staggering.

Case in point: I'm the second player on the list, i pick my role, the third player immediately picks the same role because 'he called it'. Everyone else tells me i'm wrong. The conversation progresses somewhat like this:

"Dude OMG u suck noob!"
"He's below me in the list, i pick before him, i'm in the right"
"Dude you like gotta learn to be a team player"
"How is it 'being a team player' to give him whatever he wants regardless of the actual pick order simply because he demands it?"
"He didn't demand it, he called it!"