The Chinese government has been at it for many years, on WeChat, Weibo, Renren, Qzone, QQ, etc. Having lived in China for ~5 years, it sucks but it is absolutely better than nothing. It also is not remotely like being "blindfolded, speaking to a room you don't know is empty or not". I don't feel that way on HN either though I know getting shadow banned is a possibility.
The fact is, there is some censorship and surveillance in China, and Facebook can't do anything about it nor is it exerting any sort of pressure by staying out.
I understand that it is scary for us, westerners, to watch this unfold, but for the Chinese people, gaining access to a censored Facebook would be a step forward overall (right now, Facebook it is essentially 100% censored).