In US, the taxes are a lot heavier than HK. Well... it depends on how rich the person is but...
Federal tax could go up to around 35% of your income, and you still have to pay income tax to State which would be around 7% vary from State to State. Social Security for self-employed people are another 15% or around 7.5 if you receive wages. When you buy things - most things, you will need to pay "Sales tax" which is also different from State to State around 7 or 8%.
and if a person owns a house/apartment etc, the person needs to pay property tax which could be around 2% of the value of the house.
You can see most people paid some many tax, it's much harder to become extremely rich in US with so many taxes. With all the tax charged by government, the government can distrub some income back to lower income people. Well... Will you like to give 50% of your income to government? I bet most HKs won;t like to have such thing.
The property tax can certainly bring house price down, but most people are likely to have a much worst problem if Hk government does so.