"Set aside that I can't work out from your very unclear post whether you're actually for or against concreting over the countryside"
I am in favour, as a starting point (not in all cases, but certainly far more often than we do now). We are stuck with 1950s boundaries in many cases, which are no longer appropriate given structural changes in society (household sizes, and their locations)
"To dismiss people who think we have an ethical duty to protect wild spaces both for general human well being and for our fellow species as old nimbies is frankly too stupid for words. But sadly a very common, and lazy viewpoint."
Well round our way it's certainly the reality. You will find someone with a house slap bang in the middle of a massive area of green belt opposing development a mile away.
Which is all very well, but I would have more sympathy if they were living in a city-centre apartment. Exactly who are they trying to save it for? The city-centre dwellers who are supposedly going to drive six miles out of town and stop on the edge of a dual carriageway to walk across a field, or for themselves?
And the people at the 'Save the Green Belt' meetings are overwhelmingly middle aged and older. Although perhaps that reflects that house prices have already excluded anyone who is not in this demographic.
"I suspect that like everyone else I have ever met with this opinion you also think said nimbies are selfish and oppose development near them because it will devalue their houses. One response to this- people who want more development always seem to argue for it on the grounds that it will bring prices down and they'll be able to take advantage. Just as selfish, just depends which side of the fence you happen to be on."
Those aren't equally selfish at all. The first person wants fewer people to have access to housing, to enrich themselves. The second person doesn't want to deny the first person access to housing, he wants to expand access.