The appalling lack of incentives and "nudge" social pressures last year left HK, and especially their elderly, in a poor position for the current virus wave.
The HK government have failed to keep their people protected, and the prescribed intervention of Beijing in the recent months is too little too late.
STW I thing Flying clog has it right. It is about punishing the HK people for being the errant child. The CCP has good previous on this as you remember, Tibet, Mongolia, Beijing students, Xinjiang and even the movement of the little old ladies on the pedestrian bridge in Wanchai, which we still cannot write for fear of the bot (and the half million human, English speaking email interceptors) who read our emails.
I am very sad to see my adopted country go this way. On a recent (full) flight to HKG a friend reported that nearly all the people she spoke to were coming to clear out their offices and homes.
It is what Beijing wants. Less foreign toxic influences of social democratic liberalism or Republican hands-off government. Neither is in the scope of President Xi's wishes. A Chinese city for the Chinese people.
I suppose if China had a city like San Francisco under Chinese control in the USA, Congress might get upset about it and try to move the Chinese out. Oh, wait...