If your question is in response to a visit to or a stay in China of any length, then I empathize with you and I could do quite a bit to add to your list. These are my observations based on my experience in China which I hope can help to shed some light.
1. Cultural Problems:
China is in the middle of a huge economical leap forward but, unfortunately, this financial progress is not actually having any real effect on the education system which still remains in an abysmal state due mainly to corruption and ignorance in the central government (based on 2 years of experience working in a Chinese university).
Most Chinese families have only one child and as such that one child is treated as if he or she is the only child on earth during their critical development years ("little emperors"), so it's no wonder that many grow up to be adults that have almost no sense of empathy or respect for anyone other than themselves and their immediate family.
These are two of the biggest "problems" that I have observed contributing to the rudeness that you mentioned: bad formal and home education (both possibly stemming from China still not widely accepting psychology as a serious field of study). Of course, there are many highly educated and extremely polite people in China.
2. Cultural differences
As others are so quick to point out (whilst calling you a racist bastard) there are some pretty big cultural differences between China and whichever western country you hail from.
Examples:
Directness is indeed more widely accepted in China and I found incidences of such directness rather offensive at times ("Your clothes are pretty ugly...you're not very strong..."). At this point, it doesn't phase me.
China is filled with 1.5 billion Chinese people and a smattering of foreigners ("laowai"). Depending on where you happen to be, they may have only seen a few foreigners in their life and can't resist watching a rare occurrence like you walking by.
The list of differences could go on.
If you are going to live in China for any period of time, you need to have a good sense of humor and a good reason for being there (studying the language, Kungfu, business...).
The truth is, I have many Chinese friends who would absolutely agree with your complaint. It is a REAL problem that may be a result of China's blind, ***-backwards expansion into oblivion.