Maybe not where you live, but looking at current planning permissions
being given where I am , he would have a considerably increased chance of
getting planning permission to convert an old disused building of any
description including a shed ( or even knock it down and build again),
than
he would of getting planning permission for building on land with nothing
on
it

It depends on your planners and you area I suspect.
So blanket dismissals of other peoples views as rubbish or b****** or
even
citing cases such as the one you do is not really accurate is it? Its not
polite either.

It is certainly not the case if you look at the current government planning
policy. That policy is national and not local. It comes under the heading of
sustainable development. A full explanation of the planning guidelines is
given here.

http://makeashorterlink.com/?P26135F28

All local planning authorities are bound to follow this guidance. If they
don't they are subject to sanctions by central government unless there are
very good reasons to override the policy.