Their point is that developers are legally forced to build SFH even if demand says otherwise. Detached homes are a major tax burden on cities; their cost should reflect their real cost. If you want one, go ahead and get one (I will be doing the same!), but cities genuinely cannot be built to handle most of its land being single family, detached homes.
I may want a detached home for hobbies and space, but the most fun I’ve had to date was when I lived in a townhouse in the middle of the city and didn’t need a car to get anywhere. Exploration and discovery is impossible in suburbia.
Hell, you can have suburbia, but it should still be walkable. And you do that by increasing the taxes on them (rightfully), adding regular busses, having bike lanes, including businesses in the mix, and having them not be so sprawling so that you are closer to the city itself.
Fried_out_Kombi