This is the very point my vet made the first day I was there at work. His view is that he'd rather declaw the cat than euthanize it or have it wind up in a shelter. If it's the only way to save a cat's life, then that's the reason to do it.
I can understand his view, and I don't think people are bad if they declaw their pets. My mom knows where I stand on the issue, but she has declawed cats. Good people everywhere have them in their homes. However, I think educating potential and current cat owners about it and about alternatives is always the best way to go. Where I work, if the client wants a cat declawed, that's what they get. They don't get any advice about it, so that's what upsets me. If people want cats, then why can't they try and make an effort to train them to scratch appropriately? If they have tried everything and the cat is really bad then maybe that would warrant the cruel procedure rather than having the cat dumped. I do believe alternatives should be tried first, because why wouldn't an owner want what's best for their pet? Otherwise, why get one? Or, go to a shelter and adopt an already declawed cat. I see plenty in the shelter where I volunteer...
BTW, I am one of the lucky few that have a cat with behavioral problems as a result of the declaw procedure.