When I see a springer with its undocked tail lacerated after a morning's hunting through brambles, I know which side of the fence I'm on.
I do however believe that as not everyone will agree on this subject the safest way to deal with it is to leave it to the vets. The result of an outright ban on the practice will definately result in suffering to dogs. At least if a vet does it he/she can make it safe and relatively painless.
I should add that I am involved in working dogs and I own retrievers.
I should also add that I would happily volunteer to chop bits off of owners who "must" conform to breed standards.
Lets not get on to the subject of dew claws.