There's usually no explicit reason given. And if you shake them down, they point to their TOS that states no cannabis and say you can't feature any reference to it on your website (or even social media).
It's a legal business in terms of local or state municipality, but it's still illegal on a federal level. And since all banks/credit cards are managed on a federal level by the FDIC. They risk their federal license/status if they operate with federally illegally businesses. So you end up working with smaller banks/processors that are on a lower profile, and are willing to risk their license.
You can find local processors happy to have customers, but they overcharge you 10%+ in fees (versus Paypal's 2.3% or whatever). They take so much risk they overcharge to cover it. And they tend to only offer bank wires/e-checks, since credit card processors/bank debit won't even take the risk.
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