To start with, some Hong Kong people refuse to admit to even being Chinese. I believe the main reason for this rejection of their Chinese identity is that Hong Kong was controlled by the British for more than 150 years. This greatly reduced the patriotism of Hong Kong people towards the motherland.
During colonial times, people had no relation and no contact with the mainland. They were controlled by Britain. The older generation, which experienced the hardships of the war, was not effective enough in instilling pride in being Chinese among the youngsters.
Why do young Hongkongers still dislike mainland China?
By the time Hong Kong returned to mainland China, the city’s youth had mostly forgotten the glorious history of China and their national identity. That explains why so many young people take an anti-China stance and talk about Hong Kong independence.
Wendy Wong, Kwai Chung