Salbertina Yes, and I reckon if you take tax and rent together, living in central Hong Kong is about the same as living in central London, so we can't really complain. Some things are more expensive- food stands out- but some things are very cheap, such as public transport and taxis, and critically, childcare. Overall, I think it's a case of "same same but different"
Anyway, I think you have to take surveys like this with a pinch of salt because what Expat X wants/expects ain't necessarily the same as what Expat Y wants/expects.
Personally, I think Asia is great for kids. There's so much help available, you can still have a good social life- I don't just mean in terms of going our drinking, but just having time to play sport or whatever. If I was in London with DH working all hours and traveling, and with no family near, I'd be confined to barracks every night.
The schools are good, and maybe HK and Singapore are different, but the International schools in HK are not overly academic/pushy- in fact some parents complain they're not academic enough and send kids back to board for secondary.
I find it really bizarre that China is No 1 and HK is No 10 - looking at the criteria, I don't really understand what the differentiating factors are.