+1000. But those people will NEVER leave "we" behind, because without obsessively believing they are a part of "we" they won't survive.
Come on now. They don't use it all the time.
"We won the game!"
But also:
"They lost the game."
In all seriousness, I do say it because it's just easier to insert into conversation, in terms of an "us and them" perspective when talking about the team you cheer for and the opposition.
It's simpler to say "We've got to deal with their counter-attacks better." as opposed to "They've got to stand up to their, by them I mean the other team, counter-attacks better."
It's fast and there's less ambiguity, and there's something oddly formal about using the team names in a sentence in discussion throughout an entire game.
"I hope the Senators keep it up. They've got to deal with those Penguins before the Penguins bring the puck back into the Senators end and a few of the Sens end up in the penalty box."
For the record, I don't think I'm part of the organization or anything. It's just a label.
I will certainly watch neutral games and I obviously manage - I think the "we and them" thing is just a shortcut because the vast majority of games that I watch involve the Senators.