It seems like the best strategy because you figure other people know something you don't know. But since they always pick just one exit, that's not a valid conc

It seems like the best strategy because you figure other people know something you don't know. But since they always pick just one exit, that's not a valid conclusion. Since the crowd behaves the same way whether they picked the best exit or a random one, you have no idea whether it's the best way out, but you do know it has added risk of delay and trampling.