For people who raise chickens for show, dubbing the comb & wattles is required for some breeds (rather like dog breeds with docked tails or cropped ears.)
So unless or until those breeds change their standards, dubbing males will continue to happen for show birds of those kinds.
Some people in cold climates dub combs & wattles to avoid frostbite.
I have read of a few other one-off cases that would not apply to large numbers of birds (for example, one was a pet rooster with a really enormous comb, so big it was dragging his head down and covering his eye and nostrils. The owner dubbed that comb to improve the rooster's quality of life.)