To give them a special name, in and of itself, raises phonecall spam to a new level of shenanigans, when this is something of a script kiddie skill. Same as email, this is a mild nuisance. It's not some crisis tearing at the fabric of society.
It's sort of like complaining about how windows are transparent, and that you shouldn't need curtains to prevent people from looking inside. It's like there's this expectation that it should just be illegal to look inside any window.
If it's a phone number, people are going to call it. If you don't want to be disturbed, don't let your phone ring? If you only want to be disturbed by familiar individuals, only ring for those numbers, or screen voice mail?
Seems... almost too easy to deflect this sort of thing.