The guy to his left, who had shorter hair, said "Looks great, don't cut it shorter". It looks like the pendulum is slowly swinging the other way....toward long hair on guys.
The way I see it, most men don't really care about the hair length of other men too much. I haven't seen the commercial, but is it possible that they were telling him not to cut his hair any shorter, because that way they could get out of the barbershop, and get a beer quicker?
I agree, at least here in UK, but the change can only be gradual, obviously, as hair takes so long to grow! But there has been a noticeable reduction in the number of shaved heads or suede cuts in recent months. Clearly a shaved head grows into a normal short style much quicker. It also seems that middle-aged men are growing their hair, possibly because they are returning to the style of their youth.