In this case, the very existence of teams is an invention of those who managed to make a career as team leaders. By prefacing your statements with an explicit allegiance to a team, you're in fact endorsing whoever is presenting him/herself as the team leader.
This is purely a power game in which some individuals have managed to blackmail everyone else into recognising their role or being cancelled. Now and then someone prominent needs to be attacked to remind the others what they risk if they don't fall in step.
Because it identifies which team you are on. People only recognize the existence of a nuanced point if it's made from someone on their own side.