>they seem worthy of protection?
Maybe mainlanders don't deem HK worthy of protection. Mainlanders cared about pollution, they protested, government responded. They lost their shit at poor safety due to rapid development (aviation, high speed rail, food, medicine), the government responded. They were disgruntled over pork prices. The government responded. Chinese society skews old, conservative and anti LGBT. Government unfortunately responded. Unprecedented MeToo trials happening right now. Government responding. Sufficiently significant issues that elicit widespread attention gets addressed, Chinese people advocate for themselves all the time.
> fed propaganda
Fact is pork prices is literally a bigger problem to mainlanders than plight of privileged HKers with historic acrimonious relationship. This is a well understood dynamic, suggesting HKers would have ever got mainstream mainland support because of propaganda and not bad blood is exactly the kind of anglosphere illiteracy on China I'm talking about. ProHK / pro liberal reform voices exist but not much. Why? HK protestors from mainland perspective: young, nativist, disillusioned but privileged individuals who spread shit about mainlanders on social media for years... Yeah, I just described alt-right. Is it any surprise they got minimal support. Lots of mainland diaspora in the west with access to both side of the story, did meaningful numbers come out to support HK? No, they had access to both sides of the story, they just knew better.
>integration
Of course the goal is integration, CCP is not spending tremendous resources to be cruel for shits and giggles. If Han knew how much was going into XJ they'd protest, due to costs not human rights. Like people everywhere, the public would rather the minorities rot than take disproportionate resources. But unlike democracies, CCP can actually ignore public sentiment. Some in this generation will be a shell, their descendants will be integrated. It's ugly, but things move fast in Chinese 5 year plans. None of this long arc of justice nonsense. It's not right, but history will judge relative wrongness compared to locking up 1/4 of black Americans or trapping indigenous peoples in backwater reserves forever.