When I joined, I was testing the game and didn't think I was gunna be around for more than a week, so I didn't really care during the sign-up. If others end up liking the game, but not the name they chose (because of typos or for whatever other reason), it is more incentive for them to stay if they can change their team name to something they'd like to keep. So I think if the goal is to keep more people around, this is a good suggestion (and I don't usually find myself agreeing with Naker).