No, I would argue that it's different. CNN has a limited amount of time to fill and doesn't accept user submissions. HN has neither constraint, and gives users voting rights over some of the success of each post.
I think it's entirely valid for me to present my case and submit it for the consideration of the community and the moderators. I don't understand what you're getting at here, you're not making a very compelling argument for anything in particular.
In arguing that CNN's decision not to air your opinions in prime time is legitimate while HN's decision to be selective about what they'll provide a venue for isn't, you've accepted unquestioningly CNN's constraints while dismissing HN's.
In both cases, you're applying an enormous amount of subjectivity. But you'd prefer not to acknowledge that, and so have instead attempted to reframe the discussion as if your conclusions about CNN and HN are self-evidently objective. They are not.