I'll add a triple "ditto". I agree that it's their bodies and their money; they can do what they want. But I also agree that for purely cosmetic reasons it's an incredibly stupid and risky thing to do.
I can nearly always spot it, no matter what it was - nose, chin, eyelids, boobs. It's always obvious, and usually no more attractive than the original thing was. And my immediate response is not "wow, that person looks good now!" but "wow, that person must have serious issues to have done something like that!"