I get what you're saying, but the team rivalry makes for a lot of fun interactions with people (jokingly, of course). For example, when a gym has just been taken over, or there are multiple people at a pokestop, it just gives something else for people to talk about. Also, a lot of the valor-specific backlash is most likely a result of its strength and amount of control for gyms, so there's something to be proud of! (although, in my case, anti-team posts are roughly equal with the exception of instinct, who have a little less "enemy" posts, and, when they do, they're paired with mystic). I guess what I'm saying is, it's just a game, no (regular) person is going to sincerely kill someone over their team, or have segregated pokestops, etc.