The ratio of chinese to foreigner is obviously high so it's not hard to find HK ladies that are interested in a foreigner since competition is limited however it certainly doesn't mean most of them want to meet an expat.There are also plenty(I would say the majority) of HK chinese ladies who wouldn't want to marry outside their culture.
People's experience of particular groups is also often tainted by their own actions as well as the places they frequent.
There are those who see expats as boorish, loud alcoholics who hang out drinking in Wanchai and LKF and the only reason they are in HK is because they couldn't hack it in their own countries. The game of stupid stereotypes is easily played...