Absolutely right Nick. MMC have depended on the goodwill of their customers for years, and for most of them, they can continue to do so. The challenge they face is as you say with the £80k customers, who have a completely different mindset.
The MX5 is the perfect example of what MMC is up against, it's a fantastic car, does everything a 4/4 or +4 can do, it can do it with much more comfort and total reliability, and as you says costs half the price.
If they were built in Britain and I were in the market for a new sports car I'd have no hesitation at all in buying one over and above a Morgan.
I have a self-imposed restriction of only buying stuff that's UK-built, though, on the basis that "If you want to live in a country that makes things, you have to buy the things your country makes".