They are stuck paying extortionate rent (my partner and I pay almost £300 a month more in private rent than a mortgage would cost us)
Well, this is because most landlords are amateur landlords.
Not necessarily. My mortgage agreement states that I have to charge 145% of my monthly mortgage payment if I rent it out. Consequently the flat next to mine pays a much higher rent than my mortgage for exactly the same thing.
If you make a luxury like that available to everyone, then what incentive is there to better oneself, seek out and take advantage of opportunities etc?
Well we could apply that to everything, couldn't we? What incentive is there for people to better themselves and work hard to fuel the capitalist state and pour money upwards into the pockets of the wealthy few if there's food on offer other than gruel? Why not make people accept worse living standards as a stick to strive harder? 
When you can tell me that there's genuinely equality of education, opportunity and cultural capital in this country then I might entertain this as a notion. Until then it's just a different version of the American Dream, and just as much of a façade.
Houses are still cheap by UK standards in places where there's no work.
How do you afford a house when you have no work? Housing will be cheap if no-one locally can buy it and BTLers won't touch it with someone else's bargepole because no-one wants to live there because there's no work...