It actually makes sense to me, from the perspective that I can't see anybody wanting the liability involved in letting a 91-year old man clamber up on the wing of a damned Spitfire like he did when he was 20. I don't care if he flew the things in the war. I don't care if he (thinks he) is health as a horse and hung twice as large. I'm not going to be real happy shelling out megabucks to the old guy's next of kin because he jumped up on that wing just like he was a 20-year old leftenant again, and slid right back off, breaking his fool neck. And insurance company isn't going to thank me if I put them on the spot instead.
Far as I'm concerned, the old guy can purchase the plane from the collection and do what he wants with it, or he can admire it from afar, like the rest of the general public.