Hosting providers don't care
I've made numerous reports to various hosting providers about spammers and scammers hosting their web sites on a provider. Hosting providers don't care if they are hosting scum, because
1) Scum pay them. Very well, in fact.
2) You, the person complaining about it, don't pay them.
3) There is no downside to hosting them. The hosting providers all say "as long as the spam doesn't come from us, we are in the clear."
So unless those conditions change, the hosting providers will continue to allow spammers and scammers on their networks.
I normally don't say "there ought to be a law", but in this case, there ought to be a law that says "If you host a site that is spamvertised, and you are informed of it, and you fail to take action, then you are guilty as an accessory and shall be fined heavily".
Failing that, the old "blacklist the entire hosting provider's netblock until they change" solution.
Grenade, for rectal use only by the spammers and hosting providers who love them.