What is your solution, then? The demonstrators should realize the futility of their position, give up, go home, and allow the situation to deteriorate further?
Engaging in whataboutism just encourages the bad behavior you're highlighting here. It's a logical fallacy that leads to learned helplessness and a nihilistic worldview that actually ends up perpetuating the same vicious cycle I assume you wish to prevent.
Hong Kong is China though it has a formal autonomy. Anyone who thinks differently is heading for a nasty surprise.
Protests with street violence are making nice picture for Western media but will only bring trouble for individual local protesters. Criminal convictions, lost jobs, ruined careers.
This benefits only external actors that coordinate unrest and trying to get leverage on CCP in foreign affairs.
Those committing violence -- the people in uniforms attacking protestors -- are not going to get criminal convictions or lose their jobs. This is China we're talking about.
Engaging in whataboutism just encourages the bad behavior you're highlighting here. It's a logical fallacy that leads to learned helplessness and a nihilistic worldview that actually ends up perpetuating the same vicious cycle I assume you wish to prevent.