Are uneven team balance locally ruining the gym game?
At least it seem so in my town.
The majority of players are blue, then comes red and a rather small fraction yellow. Which leads to blue holding the vast majority gyms at lvl 10 for weeks/months at a time. Red holds some gyms in selected areas. While yellow seldom gets to hold anything for more than short periods. I spoke to one Instinct player and he told me he only once had hold one gym for more than 24h.
This have spawned a lot of frustration in the locally community. From nice and easy going at the start to the present toxic relation between active gym players.
To me it seem like a rather stupid idea that people get to choose one out of three teams, instead of randomly assign people. At least if balance is a priority.
In my country several informal studies have shown that if people pick favorite colors, the majority picks blue, red comes second and only few chooses yellow. This pretty well matches our local distribution, since only a small fraction of the players have any relation to Pokemon or the teams before Pokemon Go.
Answers
Yeah I get what you mean in my town both gyms get taken over multiple times a day, but the decently big city closest to me is fully blue all 20-ish gyms of them. And they're level 10 3000+ cp so there's no way you can keep one, so there's no use trying to fight them. Only the bigger city I go to, where I is study is so big the balance kind of regained itself and there are plenty of different gyms.
Randomly assigning teams don't help even if it was implemented since the beginning. Because you can't control who will continue to play and who will stop after a few weeks/months. Also, what if it just happens that your town's good players were all randomly assigned to a team diff from yours. Then gym domination would be the same. Too many factors that would still end up skewing dominance to one team.