I personally won't hire maids.
But I can understand why: imagining you can hire a maid who will take care all house works 6 days per week and you only pay 400-500 USD a month.
If you don't mind an outside people stay with your family, it really free you from all the pains.
A lot of these types of people are very opportunistic and stingy at heart. They think because they are paying someone a salary and sheltering them, that they basically own the person and have the right to use every ounce of their energy. Imagine living with your boss 24/7,it must be a nightmare. I have known of many Au pair situations in the US involving Latin Au pairs and the circumstances become very abusive and slave like. I can imagine it’s even worse in HK where the locals are already rude and selfish at heart.