I understand if you dislike adblockers, but calling them a scam seems misguided. I think most people are well aware that adblockers prevent income for the site owners.
And you are not really giving any "benefit of the doubt" by calling them scammers straight out, are ya?
He can't, because it isn't. Their acceptable ads policy is dead clear, and yes, it takes time to verify new entries and maintain that list, so they charge money to get onto it.
Personally I use uBlock Origin for technical reasons, but I have no problem with AB+'s acceptable ads program.
Incidentally, thanks for posting, even though it incurred a karma hit for you - good to hear both sides. HN has too much groupthink sometimes.
Source?