Private companies are not the arbiters of free speech, and they should not be compelled by the government or anyone else to distribute views they don't like. This especially goes for businesses whose revenue models are based around advertising, where the financial incentives do not line up with the social benefit of their users.

I believe the proper solution here is social networks that are open, distributed, and federated. It is not for government or advertisers to decide what speech must, or must not, be discussed in the open.