So aside from this being dangerous I think it's important to talk about the implications of banning the current sitting President, soon to be ex-President.
These are private platforms, and legally-speaking they should be able to do what they want. If the government says that they have to allow X, or must ban Y, then you're giving the government a dangerous level of control over speech. If section 230 is repealed, then you're giving these companies a huge incentive to delete anything even remotely controversial, since they could be held liable otherwise. In either case, you're discouraging competition to the huge companies because you're creating a situation of regulatory capture: big companies are better-able to handle burdensome legal regimes. For example, a few years ago Congress carved out an exception in section 230 for certain sex crimes. As a result, Craigslist had to shut down their dating sections because they didn't have the resources to moderate them strictly enough. Later, Facebook created a dating service, since they have much more resources, and they can deal with the 230 carve-out. Regulations lead to centralization at the top.
If you don't like how these companies do business, then use a different site. There are ways that this is bad/uncomfortable, but the alternative ways of possibly handling it are much worse.
As for the decision to ban this stuff itself: I can see how honest, well-meaning actors at these companies might justify their recent actions. Many of the people who participated in the capitol riot thought that they were doing the right thing, and maybe didn't even realize how much danger they were putting themselves in, but yet a few of them are dead and many of them are going to prison for a long time. People at these companies might reason that too many people are just too susceptible to being manipulated, and at least the top platforms should try to protect them from themselves. The most persistent believers will go elsewhere, and they should have the freedom to do so, but by having the most popular platforms cultivate their communities more, they might actually succeed in reducing the future growth of some of these crazy thought-bubbles.
There is a big risk, however, that this just creates more division. These people can go to Parler, and if Parler is gone from Google Play then they can create their separate app store. It leads down a road of basically splitting the Internet in two, and then we're going to have two almost completely separate cultures of people living amongst each other, which is a dangerous situation. Also, I think you're right in that a big part of their motivation is in appeasing the incoming administration, and these companies do have a history of being very biased. The recent decision by Twitter was clearly them just jumping onto a bandwagon, not a principled decision. IMO they'd be better-off trying to completely redesign the structure of their sites with the goals of 1) making manipulation more difficult and 2) not even giving themselves the opportunity to let their bias affect moderation. It's a difficult problem, though.
Speaking of censorship - any comment on this? https://medium.com/@johnblocke/a-brief-and-incomplete-history-of-censorship-in-r-bitcoin-c85a290fe43
