This time wasting is actionable as far as I'm concerned, but spam can't simply be banned, any more than junk mail can be banned just because a few people don't like it. There are probably a few lonely souls who read spam. I don't know, but let's assume so. When they ask whether you don't want to be on their mailing lists, they actually remove you from them. The people selling these lists have no ethics.
Legislation is required.
In it would be the names of people who have requested not to receive material. Any rented mailing list would then be checked against the request list, and the people whose names matched would be removed from the mailing list. There's a financial motivation not to send mail to someone whom it will anger and who will probably not buy anything anyway. So this voluntary system works well. Unfortunately, it will never happen voluntarily with spammers.