Well, there are things you can do about it, but I didn't want to get into that when describing the incentives that make it difficult or impossible for them to censor the public discourse unilaterally, but possible to do as a cartel. I think it's important for people to have a solid factual understanding of what's going on in order for their normative judgments, and the plans they make based on those judgments, to be well-founded.
The "logic" depends on the normative judgement that what would result from a free market would be bad
No, none of the cause-and-effect relationships I described depend on anything being bad. They function in exactly the same way regardless of whether that would be good or bad.