I agree with your sentiment, but declaring that a company shouldn't be free to decide who they can and can't do business with isn't the solution to this problem and I am no friend of the business world.

It seems fine now when it's something you don't like but what happens when it's a situation that isn't so agreeable? like being legally oblidged to do business with South Africa during apartheid or working with a chocolate company that (allegedly) used child slave labor to farm it's cocoa??

A payment processor should be treated like a utility. They just let the money flow and skim profit off the top without caring who's at either end.