I mean I don't know, if you told me that the Chinese government is going to try to get an extradition bill passed that could allow them to abuse this power to take people from Hong Kong into Chinese custody (which is notorious for some shady things) for simply not agreeing with the Chinese government, I think I'd be pretty angry too.
This is like saying: Why are you so mad that I didn't allow you to speak freely?
That is actually one of the reasons why this protests leads into a very disastrous acts because in the first place we all know how Hong Kong people usually criticizes the main land China's government. At first they are speaking out because they wanted to tell the Hong Kong government not to fall into the trap. But then it seems that they were being censored by the government that makes them more angry because of that "freedom of speech".
The Chinese government deserves all the hell that they're getting right now, and they deserve to have to succumb to the sheer force of numbers of the people in Hong Kong.
Actually this is not the cased right now. Hong Kong people are trying to ask help for the international community because their government wouldn't listen to them. Then Trump made a statement that this issue is only between HK and China which is actually a pretty bad sign for the Hong Kong people. In this case the Chinese government might be able to have a full control over HK then everyone who will try to oppose it might be in great trouble.
Most western nations are trying to stick a weird balance between working with the Chinese, and protecting Democracy in the world -- which they have been trying to do for a long amount of time now.
Hong Kong is even a more special case, as there was an agreement between the Chinese and the British to ensure that Hong Kong would have their own separate government for a certain amount of time (I'm pretty sure that's how that worked) And now they're failing to work within that agreement, as they continuously meddle within the HK government -- and this is just one of the many examples.
HK is not in big trouble now, they've been in trouble for a long time as they're sadly under the control of the Chinese. We'll see what the future holds though.