People in China, at least those millions people who are able to cross the Great Firewall, know that democracy is generally good, but they also know that a strong central government can also be useful for certain circumstances. Most westerners and HongKongers on Hacker news have a very extreme political view, you just believe "democracy is good"(TM), protesting against the evil Chinese government is good. But can you take a closer look at what is really happening in HK and then decide what you believe?
BTW, I'm neither pro-protester nor pro-police, I think the protest is a result of economic regression in HK. You could also check my comment and posting history to see that I'm not a 五毛党.
Is there an equivalent instance of the Tiananmen Square massacre in the US? (I'm asking, I don't know).
The US has their fair share of issues but freedom to speak against the government has always been a big thing.