The banks do. Payment providers do. Advertisers do. There's plenty of reasons for a business to be low-key about providing accessories to break Federal laws.
No they don’t. They just want plausible deniability. They’re a bank, they want to make money. Every dispensary has CC processing and a bank account. If they cared about federal law, they would stop obvious money laundering.
EDIT: Just read the company is issuing and processing their own 'credit cards'. I'm positive I've only used cards when buying from our dispensaries. Come to think of it, it's just debit cards but it's a card and it will buy weed if you want it to.
Point being, the large credit card networks, and more importantly, any FDIC insured bank, will not deal with cannabis funds.
There are a number of workarounds (Colorado credit unions being a notable one), and fintechs like the ones described in the article you linked trying to provide card solutions, but they're still all locked out of the "normal" US banking system.
"and more importantly, any FDIC insured bank, will not deal with cannabis funds."
This is patently false. My close friend runs a $75M/yr wholesale distribution op out of Carpinteria, Ca, called Headwaters. He has multiple FDIC banking relationships for his business.