Partly because their military is going to get smaller and smaller as the years go by because their population is declining. For a country that claims they think in terms of centuries that one child policy was a not well thought out. No one ever said commies were the brightest.
They still have more military aged males than anyone else and that's not changing.
China would probably be more than happy to kill off some of them to avoid unrest as a matter of fact....
But yeah you're right. They usually "solve" one problem and create another worse one from the solution.