Much ado about *censored*

I think it's a bit more nuanced than that. It isn't just customers they don't want to offend, they also may wish to curry favour with powerful interests. E.g., the state, because the tech companies wish to keep in the good books of the state so as to either obtain or avoid regulations that are or are not in their self-interest. So tech companies may well censor material that goes against the government lines - be that political speech or even objective scientific factual material. This may happen at scales that it has a significant distorting effect on public discourse, and so affects important public policy (either by changing what is implemented, or delaying required change).

tl;dr: Tech companies have a demonstrated tendency to apply editorial control over both their own output, and what they allow users' to publish, to curry favour with the state - and other powerful interests.

This is not at all done in the interests of customers. And (whatever they say) it is not in the interest a of healthy civil society.