I think another argument is about what constitutes a "fair rent". £150 a week would not get you a flat in Milton Keynes, let alone London. DD and BF were paying £900 a month for a 1-bed flat in Hackney 2 years ago before they managed to buy a tiny 2 up 2 down Victorian terrace in Walthamstow. I am not advocating profiteering, but if councils can't charge an economic rent, then surely the rent is subsidised? If subsidised (and I would be the last to argue against subsidised social housingwhere needed) do tenants not have to meet certain criteria?
The principle of buying council houses at a subsidised price took a massive swathe of housing out of the letting market, these houses were subsequently sold on - frequently for massive profts and the councils not only didn't benefit, but future tenants were then forced back into the private sector. We seem to have sunk to a level where housing associations have taken over social housing where council housing left off and councils have lost out on the opportunity to be responsible landlords and to reinvest the income from their housing stock to provide more or other necessary services. The principle of owning or not property doesn't apply to a hell of a lot of families, the phrase "chance would be a fine thing" springs to mind.