This is a very common question, and understandably so. It can be surprisingly hard to defend a
general principle on ethical grounds. Principles are justified by observed regularities. Good principles do not necessarily lead to correct actions in 100% of circumstances.
The principle of “don’t interfere with the free exchange of ideas” is one such example where it is particularly hard to see the justification. The consequences of speech suppression are usually subtle —- how do you quantify the impact of a conversation that didn't happen? And at the same time, the consequences of allowing hatespeech or misinformation are usually not subtle, but rather immediate and relatively obvious.
I think we’re actually lucky because the Joe Rohan example does contain examples of good justifications. For the past two years, Rogan was openly discussing politically inconvenient inconsistencies, contradictions, and in some cases retroactively apparent lies by the establishment. It is good to know when your leaders are incompetent, when they are lying, or even when they have made a mistake and never taken responsibility for it! It is good that these conversations happened and good that people know this information.
But even if we can see that this is good, it’s still one of those abstract good-for-society things that is hard to quantify and hard to weigh against the consequences of its counterfactual non-existence. It is thus almost impossible to balance against the harms of, for example, supporting vaccine skepticism. But that’s not an argument for suppression, merely an acknowledgement that this is hard to think about clearly.
But it is a fallacy to say: Joe Rogan’s vaccine skepticism is getting people killed, therefor he should be silenced. The reason is that living in the sort of society that would silence Joe Rogan also gets people killed. The deaths are just abstract deaths.
Put it this way: image we get into a war in five years because Rogan and all the other independent voices like him have been successfully soft-pressured into not talking about the downsides, while the mainstream propaganda mouthpieces have been selling the war hard. Thus, we create a concrete terrible outcome because we allowed a culture of speech suppression. Unfortunately, even if that does happen, it will not be obvious that speech suppression led to war, because, again, general principles tend to have more subtle but far-reaching consequences.
There are also well-known edge cases where speech suppression is probably obviously the right thing to do. I personally think that the genome for smallpox should never have been published, because try as I might, I can’t imagine a scenario where the harms of suppressing the specific knowledge outweighs the possible (even likely) consequence of its dispersement. You can have a principle while being cognizant that tradeoffs can be valid.
Again, though, the reason why free expression is weirdly difficult to defend, is that the harms of “bad” free expression are usually immediate and clear, while the harms of speech suppression are abstract and distant.