I think there are times debarking can be a benefit to a dog. Some just are neurotic barkers and nothing works.
I would much rather see a dog debarked by a vet than passed from shelter to shelter or on meds that it doesn't really need or even PTS.
If done by a vet it certainly isn't any harder on a dog than spaying or neutering or even dew claw and tail removal. These are all procedures done by owners choice as well. I'm sure no male thinks he needs his family jewels removed.
I don't believe it should be used on a whim but won't condemn everyone who does it as being inhumane.