Housing is a basic human right. However you can deny housing to someone because they belong to a hate group.
Running a profitable online business is not even a basic human right. No one owes you payment processing. Forcing someone to be a supplier to a hate group violates their basic human rights. If payment processors were discriminating against a protected class such as race or age then you might have a point.
This doesn’t work when it’s something basic like payment processing. It’s the same reason we decided as a society that people can’t “trust their gut” and deny housing to people based on the color of their skin.