The videos suggested by Jonkster answer all my questions and make perfect sense. Basically customer resistance to change, and lack of cash all round.
Very interesting .
Pilot DAR:
Good luck with the project. Will be interesting to see if it changes minds.
David Gittiins:
I have owned cars from those built in the 1950's until the present day (including a Morris Minor, MGB, Landrover, VW and Mercedes). Since then, none built with modern electronics have ever failed to start first time, or given me any trouble at all, although I guess that, if they had failed, it might have been expensive to fix. But maybe I don't drive them hard enough or have just got lucky.
Will get back into my shell: thanks everyone.