Downvotes are primarily going to be from people who would prefer that wasn't the case.
However, I believe most accessibility improvements must be "reasonable" accomodations and generally I think aren't intended to be onerous costs (unreasonable).
So there's room for debate on whether accessibility should NO LONGER be a right in the USA. And also room for debate on what's reasonable.
But I don't think this statement: "accessibility is a right" should be downvoted on HN. Its a fact of law, due to the Americans with Disabilities Act.
This is a global community, though. Many probably interpret the statement from a moral/idealistic standpoint rather than whether or not it's a legal right in any particular jurisdiction.
You can't say 'well disabled people aren't the target demographic, so no I don't have a ramp' any more than you can say 'whites only'.
The other commenter didn't claim it was a moral (as opposed to statutory) right, but even if that was the intention, I think that's a reasonable position to take and argue for, even if others disagree.
One standard proposed at HN from time to time is that maybe websites with high revenue should be required to conform with a specific standard such as W3C's WCAG 2.1 AA.
But it's an open question and I don't know if lawmakers are even aware of WCAG, that would be nice.