Understandably, grievances don't excuse the violence and destruction caused by these people. But it doesn't mean we don't need to understand how the oppositions, traitors, and foreign agents incite fears, prejudice, hates, and ignorance through grievances.
The root causes of many of today's problem can be traced back to the colonial years especially at the very end of the colonial rule. After the failed attempt to persuade the Chinese government to delay the handover by British and the failed attempt by Pao Yue Kong(with other HK business tycoons) to set up a plan to pay the central government $10 billion HKD to lease Hong Kong for 10 years, the British government and the HK business tycoons colluded to enrich themselves before the handover. The results are the following:
1. HK has become the world most expensive housing market with a price of $2090 per sq ft and one of the most expensive rental market with an average monthly rent of $2700. The average living space of each HK resident is 170 sq ft compare with 270 sq ft in Singapore. 27% of the HK government revenue was from land sales.
The waiting list for public rental housing around the handover was 6 1/2 years. Hong Kong Chief Executive Tung Chee-hwa has attempted to resolve this through building 85000 flats per year but was forced to step down but his plan did bear fruit by lowing the waiting time for public rental housing to less than 2 years between 2005 and 2009. After Tung was forced to step down, Chief executive Donald Tsang dismantled and scaled back all housing projects and Hong Kong ended up to become the world most expensive housing market.
From what I see here is that initially the central government did understand housing is a major issue and grievance for low income families but somehow they let Chief executive Tsang and oppositions usurped power. Donald Tsang is on business tycoons payroll so nothing was done to alleviate the housing prices.
2. British dissolved the powerful "Special Branch" in 1995 and amended many local laws to weaken both the government and police force. Also British passed many laws before handover to strengthen the media, civil rights, and political freedom. I don't think the central government and HK government realized how weak they have become until occupy central and recent riots. The end result is that nobody fears the government or HKPF anymore.
3. British has ensured that the judicial branch would be seated by foreign judges from British, Australia or other common laws nations by preaching judicial independent.
4. Hong Kong has followed small government, laissez-faire policies for decades, limiting government intervention in business. That created a lot of problems such as the medical council. education and the HK Journalists Association. These self-regulatory bodies have become a major problem.
For example, the HK Journalists Association was the formal body to register journalists and issue press credentials. Since the HK Journalists Association is controlled by oppositions, they turned a blinded eye to the fake press credentials. In a normal circumstance, the HK government should revoke the HK Journalists Association's ability to issue press credentials but nothing is done.
Another example, Hong Kong has a shortage of medical doctors and nurses but due to the fact that the medical council is self regulated. Hong Kong doesn't allowed any foreign doctors or nurses to practice in HK. In addition, any medical malpractice is investigated and ruled by the medical council so pretty much doctors or nurses wouldn't get punished even they are at fault.
There is also the HK educational system. It pretty much is also self-regulated. Nothing is done to prevent teachers from teaching anti-China propaganda.
All I want to say is that the HK government and pro-Beijing legislators are weak and pathetic. They have allowed the oppositions to usurp powers from them. They never dared to confront hard issues and make necessary changes in education, media and judicial. They have gotten too cozy with the business tycoons. Whatever temporary peace they got with the rioters would not last til they act decisively.