Its a spurious argument. For a lot of motorists a car is not a tool it is a status symbol that proclaims (to their ill-judged minds) me car = success, you bike = failure, which of course is bollocks.
One of the many reasons I'll crack open a bottle of bubbley when she goes is this little gem from Thatcher:
"A man who, beyond the age of 26, finds himself on a bus can count himself as a failure."
I would imagine that sort of attitude, also applied to cyclists, sums up the 'mind'-set of her ilk. 🙁