There are people behind those connection requests. I don't try to guess on my server who is a bot and who is not; I'll make mistakes and probably bias against people who use uncommon setups (those needing accessibility aids or using e.g. experimental software that improves some aspect like privacy or functionality)
Sure, I have rights as a website owner. I can take the whole thing offline; I can block every 5th request; I can allow each /16 block to make 1000 requests per day; I can accept requests only from clients that have a Firefox user agent string. So long as it's equally applied to everyone and it's not based on a prohibited category such as gender or religious conviction, I am free to decide on such cuts and I'd encourage everyone to apply a policy that they believe is fair
Cloudflare and its competitors, as far as I can tell, block arbitrary subgroups of people based on secret criteria. It does not appear to be applied fairly, such as allowing everyone to make the same number of requests per unit time. I'm probably bothered even more because I happen to be among the blocked subgroup regularly (but far from all the time, just little enough to feel the pain)
Some states are more stringent with their own disability regulations or state constitutions, but no state anywhere in the U.S. has a law that says every visitor to a website has to be treated equally.
Equal protection is indeed not the same as equal treatment. No, it really does say that everyone shall be treated equally so long as the circumstances are equal (gelijke behandeling in gelijke gevallen)
As an aside, I'm curious by how that language in the Dutch constitution actually works in practice. Is it just a game of distinguishing between situations or people to excuse disparate conduct? It seems like it would be unworkable if interpreted literally.