I prefer cqb and that has been my mainstay for the last seven years. But never felt the need for a helmet and I don't play slowly and softly.
People wear helmets for looks and those that try to claim protection is a bit of a reach. They are good for taking the bb sting out because that can make you jump sometimes but a hat is almost as good. A few might genuinely wear them believing it will help with the protection but lets not kid ourselves that many do.
I have no problem with people wearing them but lets be honest about why they do.