Lack of choice for one. In public housing you get allocated a space according to some bureaucrat's tired Friday afternoon can't be arsed perception of your most basic needs, not what you want.

It's just you? You get a "studio", i.e. kitchenette, table and bed all in one room, separate bog and shower in a tiny cupboard if you're lucky. Want a separate kitchen? No. Second bedroom for friends? No. Garage for the car you don't want nicked? No. Extra room for your instruments? No. And it's in a shitty area too, here's your free stab vest. You'll also want to buy some nasal protection too because you're on the 27th floor and the piss-filled lift hasn't been cleaned in 15 years.

Oh there are four of you? Parents share a double (no it's not big enough for a king-size bed), kids share a room. One two-bed flat coming right up, complete with all the same refusals and one vest. There is one concession though, we don't put families more than 10 floors up.

Buying or renting gives you the choice to live in whatever you want, wherever you want, providing you can afford it. Of course if you can't afford it then you have to rely on handouts and you just have to be happy with what you're given.