This happens in places that are more like public squares. The drowning out is done not by website employees, but by other commenters. My comment is not about legality. It's about society. A society as I've described doesn't value free speech, it's just a bunch of short sighted individuals who only value their own speech. It values free speech in the same way a political party that wins elections to abolish democracy values democracy.
Underlying free speech: Does the society value the interchange of ideas, or does everyone just value their own ideas?
Free speech is a right. Listening to people (when they are polite and reasonable) is common courtesy. I agree that many communities, especially online communities are lacking in that area.
Rights are legal, so they represent minimum viable behaviors. Value in a society is embodied in behavior that goes beyond this. It's the difference between an organization where people are really working toward a goal like quality, or if they are lawyering the rules.
Underlying free speech: Does the society value the interchange of ideas, or does everyone just value their own ideas?