I don't really understand this. Isn't it about as surgically invasive as getting a pet spayed?
Does the scent gland do anything more than just stinking? For a cat, removing the claws literally removes bones from them. It limits their mobility and hurts like hell.
(Not that I want a pet skunk. Just curious as to why it's unethical)
I mean, you're removing part of a living animal for human convenience. If the ethical issue isn't obvious I don't know what to tell you.
The practice has been banned in the UK for almost 20 years, under the exact same laws as ban declawing cats. It's unnecessary mutilation with no medical justification.