> Can you give a couple of examples of how you feel it is arbitrary?
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.
And you are not really giving any "benefit of the doubt" by calling them scammers straight out, are ya?