Anecdote: we talked with every payment processor around for a product we were making that involved storing and spending value from a digital wallet. It was close enough to various Visa/MC rules and money transmitting statutes that the usual response was arguing for a few weeks about why we comply until higher management decided something akin to: well if you had a lot of volume we’d take the risk dealing with it, but you don’t so it’s not worth our time.
Last ditch effort was Stripe, who said: sure! And we asked again with more detail, making sure they saw the same issues and wouldn’t make us tear it down in a month. They said: sure! Did it a third time higher up for diligence, and finally just came to the conclusion they have different priorities and are getting big enough to use their scale to throw some weight around for all the small merchants.