It may be correct to say that it's difficult to get 'true friends' in HK, but it may also not correct to say so. I am a local and have been on and off trying to meet nice and decent friends (with locals & expats) and I have had both bad luck & good luck. I would like to share some of my ‘experience’, which may not be all correct. Just a sharing though.
Personally, I think some people have problem in having friends with whom you can talk sensibly and hang out like 'normal mates' (or what you say 'true' friends here) is because they limit their gathering to 'clubbing'. (I admit that I, like the majority of people, usually start the first few gatherings in pubs where give you noisy atmosphere to kill off dead-airs, if any) Every time they meet, they meet in a pub, drink and then talk, laugh a lot and say goodbye. When you get up next morning, you can hardly recall any 'significant things' you have talked to these people. However, you go on having these kind of meet ups for a while then get frustrated because these bunch of friends seem like "friends can only having fun but no more".
And, some people just sit at home after attending some gatherings rather than inviting your new friends out for more exploration of their character, their hobbies, etc. So it ends up feeling the same - no friends.
We are all different - the reason we can be friends with someone but not with some others because we share something similar (hobbies, chat topics, life values, jokes, background whatever). If I notice someone whom I think I can befriend, instead of going to pubs, I will try to do other stuff with them, such as playing sports, hiking, beaching, going to the movies, or, if I know they live close-by, I will simply ask them out for a cup of coffee to spend a lazy afternoon in chats, etc. Then gradually, you will get a better idea if you guys can really get along together by the time you have contacts more in a varied ways, I mean in a ‘varied’ ways! Sometimes I have bad luck because either myself or my friends lost interest in meeting up so friendship has gone; but I also have made some really good friends and still keep contacts on and off, which I consider 'good luck'.
Anyway, it takes two to tango. When you find someone you like to befriend, you have to see if that person feels the same for you. You can't force it. Friendship grows naturally but we also need to give some efforts and, most importantly, sincerity. Personally, if someone only want to meet up for drinks but nothing else, from my own experience, there is very remote chance to build up ‘true’ friendship with them. It is not difficult to meet new people (from this site, for example), but you have to know how to develop it into 'friendship'.