If people are willing to pay $750k for a hdb flat in Bishan, then it's no longer the government jacking up the prices. If today a top floor HDB apartment at Duxton was on sale for $800k, I believe a lot of sinkies will want to buy.
The government and residents don't pay for the malls. But the presence of the mall jacks up the prices of the homes in its vicinity. Same for building polyclinics, community centers, PAP kindergartens, RCs. There are nice parks in my bukit timah neighbourhood like the botanical gardens, railway park and bukit timah hill hiking trails. All those helped somewhat to jack up the price of my property. Are those asset enhancements that we should reject?
I'm suprised that you even brought up HK as a defence for your property arguments. HK is probably the world's most notorious case of land profiteering. Regardless how profitable their MTR is, it is done by jacking up rents for their tenants to astronomical levels. Vast majority of HK ppl live in apartments that's too small, poorly maintained and they face very very long waiting list to get their own apartments.