They probably do regard JD as a bulletproof brand. My favorite
bulletproof brand story is Harley-Davidson: during "the dark
years", quality was so low that the brand new bikes would leak
oil on the showroom floor! I seem to recall that it was mis-
management rather then calculated neglect, but a better Harley
historian would know the story better than I do, and could
probably tell the effect of motorcycle quality on sales.
A funny thing about bulletproof brands is the "quiet transition".
Could a quiet transition have prevented the backlash against
"New Coke"? Just slowly change the formula without mentioning
it, and hope no one notices? (I know, that wasn't the point of
New Coke, but the question still stands.)