It still leaks information. How many kids you have, their name, some things about their personality, who they are friends with, etc. Think about how someone who wants to hurt or control you could could use that information.
The Chinese government is the last entity I'd be worried about with this kind of information (unless, of course, you live in China). Certain criminals in your own country are a much bigger concern.
This is similar to the concern some of us had over giving local government departments access to our full Opal card public transport travel histories here in Australia. Not all government employees are up to no good, but some are. Don't give them more than they need.
"Someone", sure, but not the Chinese Government! That's a completely different threat model!