Editorial discretion has always been a thing - you should absolutely be able to publish your own speech on your own terms, but I'm not convinced you should be able to force other private companies to host your content. The ability to publish widely is relatively new, before if you sent some long screed to the new york times they just wouldn't publish it (you could publish it yourself, but likely wouldn't have a huge audience).
This gets tricky though when you're talking about things like being blocked by a domain name registrar or something.
Even with speech you publish yourself there are some existing restrictions (libel laws, hate speech targeting individuals, etc.)
Moderation is also what allows communities like HN to exist and remain interesting places - I'd definitely prefer it to every website turning into 4chan.