Hmm, maybe, I haven't thought about it much. The angle I'm taking is, as a private citizen I choose not to do business with entities I think are immoral, such as Amazon and Home Depot and Hobby Lobby and Uline and Tesla. If I were a business owner, I would prefer to continue to not to do business with those entities and I'd be pretty pissed if I was forced to by the government. That does seem to agree with your "same rights as private citizens" framing, yes, though I'm not sure I'd go so far as to defend the CU decision. I dunno. Interesting question, I'd welcome your thoughts on this.

Regulatory capture and regional monopolies aren't going anyway any time soon. Let's throw out another hypothetical.

How would you feel if the only broadband ISP in your area automatically blocked entire swaths of websites from you on the grounds that the ISP felt they were "immoral" (whatever that means)? And yes I know VPNs exist but that is missing the point.

Payment processors are "pipelines" in the same manner as ISPs should be. If the major ones (VISA/MC) block you from doing business, that's putting someone's entire livelihood at risk.

EDIT: For clarification, I agree that antitrust has never been weaker and that we do need better trust-busting. I just think that it is more realistic to focus on legislation around payment processors MC/VISA atm.