I kinda see it both ways.
Yes - people shouldn't be overstretching, but the reality is - house prices have gotten so damn expensive, unless you earn a ton of money - pretty much everyone is going to be overstretching themselves to buy a house in the last couple of years (before this charade)
People just want decent places to live, if you have a family and you need 3-4 bedrooms, a garden and garage - unless you're right up north or in a real crap area, you're going to need in the region of £340k to get anything relatively standard. If you're in the south - basically forget it now.