Retrochic. No, I understand it completely. I do not deny that retiring farmers have a problem in that they want to leave the farm to their offspring, and they have more than one, where do they retire to? But the solution of taking a 'planning gain' (for the uninitiated who are interested, this is when a piece of lower value land is granted planning consent for a dwelling, thus vastly increasing its £) to enable themselves to buy a retirement home else, or else leave a valuable 'untied' dwelling to a non-farming son is unacceptable if it results in more houses in the countryside.
That's a good principle to start with - individual cases may have to vary on their own merits, or the ability to afford a good planning consultant.
Back on track - Fidler was not, and is not, a farmer - both Gromit's and your own assertion. Here's potted version:-
He built the home without planning permission in 2002.
He kept it hidden until August 2006 but was ordered to demolish it in 2008.
He appealed on the basis that it had stood for four years without anyone objecting to it. When he removed the bales he believed the structure would no longer be subject to planning enforcement because of a legal loophole.
In March 2007 the borough council issued an enforcement notice
In March 2008 this was upheld by a Government planning inspector. The inspector ruled that the removal of the straw bales constituted part of the building works and the four-year immunity rule would not apply.
In 2010 the High Court was asked to decide whether the removal of the straw bales and tarpaulin was, in the eyes of the law, part of the 'building operation'. It hung on a legal point that he lost so he bought a herd of cattle in about 2010.
He submitted a new planning application in February 2014 to retain the house on the basis of agricultural need. This was refused in April.
He has now taken this through the legal process to the High Court and lost again.
This case has such high visibility that he needs to demolish it.