Because a) Visa/MC’s core competency isn’t navigating the fraud-ridden waters of high risk transactions and b) Visa/MC are scared of possible legal consequences of engaging with these businesses. It’s just not predicted to be profitable for them.

Visa/MC are relentlessly profit-oriented. If they’re not engaging with entire market sectors it’s because they don’t predict it to be profitable.

I’m a bit confused by your second paragraph. You can still transact with CCBill from MC/Visa. CCBill is like Stripe for high risk orgs.