Most of those annoying and stupid individuals are from the so called China's Lost Generation. I found the following video made by two westerners explains the reasons in a pretty accurate way.
The problems with the lost generation are sophisticated, partially caused by the lack of education, but also the wrecked economy at Mao's era, worse than that of North Korea these days. Even worse, Mao blindly followed Russia to encourage baby booming, and there were consecutive 3-year natural disasters around 1960, consequently all these caused severe national wide food shortage. Lots of people died of starvation, for the rest, they had to do everything to just survive, regardless the means were either moral or evil. That's where the lost generation came from. Would they care Confucius? of cause not, part of Mao's culture r8n actually encouraged them to somehow not to believe in the traditional culture, of many that includes Confucius.
Fast forward to now, people of the lost generation are mostly retired and free, and some also have the money to tour around, definitely not all, but given the overall population that's a huge number of people, especially when compared to other places in the world, no wonder they were called locust in HK.
Luckily, things improved a lot, both the education system and economy wise, that's why you can see the young generation, who you probably communicated with, are mostly kind, or at least much better compared to the lost generation, and they'll bring even better education and economy to the following generations. I'm holding a good faith, and hopefully so are you.