More affordable housing for London?

"Affordable housing" is a phrase which needs to go on the banned list. What does it even mean? Something to do with affordability, and something to do with social (subsidised) housing. Mira Bar-Hillel of the Evening Standard notes the wikipedia definition - affordable for someone on median income - coming to a back-of-an-envelope value of around £100,000 (assuming a mortgage of 4 times a £25,000 salary).

She then seems to go off the rails a bit discussing the application of this concept to an actual development - the new central London Mt Pleasant development.

"of the 700-odd flats proposed, fewer than 50 may be for social renting. It also means that, based on current prices in the area, the private flats could easily fetch a total of over £4bn. And be mainly sold to foreign investors.

So based on those numbers (£4bn for 700 flats), each of these flats could sell for more than £5 million each. And the Evening Standard's Property and Planning correspondent thinks Britain should be selling off £5 million pieces of real estate for £100,000? Is it just me or does that sound totally insane to anyone else?

Meanwhile Labour councillors are angry about Royal Mail being "hell-bent on packing in as much private housing as possible" whilst there are "huge housing shortages in London." Does Labour want less homes in London or more homes?

Why does housing policy inspire such epic logic fails from otherwise seemingly intelligent people?