Ah, sounds like snobbery to me !When the question was raised (by someone) about what would happen if your old vehicle didn't meet their criteria, the answer was pretty much along the lines of "hand in your v5 and buy a compliant classic vehicle instead".
"We don't consider your crummy little car a classic, so we are going to redefine classic to mean just the cars that we own and nothing else and by doing that we'll make our cars even more collectable and therefore valuable."
Having said that I went to the 1000 Classic Cars at Cholmondeley Castle the other weekend and I have to say I disagree with their criteria which is anything 15 years or older, I don't own a single vehicle that is less than 15 years old but I don't consider my wife's Pug 306 or my Hilux pickup a classic

That reminds me a few years ago we were at a show and this know-all came round pointing out all the non-period bits on our cars and generally being a pain in the derriere, so one us said "Ok let's have a look at your car, show us how it should be done" to which he replied "Oh I haven't got one" at which point he was told "Well once you've got one and you've spent your time and money keeping it on the road you'll see why we've done some of the changes from originality, until then Sod Off"You get the same sort of rubbish with shooting organisations wanting to lobby government as to what is licenceable and not, over here anyway. The jobsworth know-all, creeping jesus type."