Earlier quoted context omitted.
I said why in the sentence before the one you ran off with. Because they get higher than usual chargebacks. This is due to the "I shouldn't have spent money on that" feeling when the user is done with the service. You'll also have fraudulent cards because there's no physical location they need to order things to to test that the card works. Probably an aspect of underaged users using parents cards due to the nature o…
So charge them a slightly higher fee to account for that. Your reasoning that that in itself would be sufficient to refuse service does not hold up.
I heard porn sites have a CC processing fees of 20+%.