My turret is so much better at this game than I am.
Why does the winning team get the new player?
It’s unfortunate, but it probably has to do with the way they’ve done the system. As you’ve described, the situation occurs when the teams have an even number of players and one is losing. If you put the new player on the losing team, though, they can just switch right over to the winning one, because it won’t cause one team to have 2 or more players than the other. And if the new player doesn’t decide to switch, one of the other players on the losing team is still free to jump ship and go over to the winning side (until another player joins the game, at least). There’s no way to stop the winning team from getting an extra player until there’s an even number of players in the game, which may never happen. They probably don’t want to disable team-switching mid-match, though, because that can interfere with friends joining other friends in games (which I’m sure would cause its own little uproar, knowing this community). It actually kind of makes sense the way it is now, since by placing the new player on the winning team, you keep them from wanting to jump right out of the match again, and you prevent players on the losing team from bailing out on a bad situation that they’ve contributed to and stealing the win. It still sucks for the losing team, but unless they redesign the system, I don’t see a great solution.