I think that this is a very old perspective on Hong Kong, whilst before it was an integral part of their economy, now that is much less the case.

As this vox article states correctly, Hong Kong used to make up 1/5th of their entire GDP. But with expansion and growth in cities across the country, it is now but a minor component of their economy. In the grand scheme of things it isn't a large enough chunk of their economy that they couldn't afford to lose it. Especially not if the balancing act is, bomb this one city and regain political stability vs massive instability for the greater entity.

[0]https://www.vox.com/2014/9/28/6857567/hong-kong-used-to-be-1...