Your view on the viability of it is grossly underestimating the hurdles you face, but lets run with it for the purpose of this discussion.
Our comparison point is a cake decorating business which refused to create custom cake decorations for a gay couple and a state law that would have forced them to do so was found unlawful.
To this, this HN replies is evidence that banks should be able to discriminate capriciously, and that anyone with a mere 50 million dollars can start up their own if they don't like being cut off by the incumbents (or don't like that their preferred choice was intentionally destroyed like SVB).