Car companies have far less freedom in car design. Activist groups and the insurance industry have pushed the government to continuously restrict the design elements a car manufacturer may alter.
Then the are the various "consumer" groups who have a huge influence on car design. I saw this with stereo equipment starting in the 1980s; They created these checklists of features, and rated products based on whether these features were present. Thus, stereos suddenly became festooned with crap that altered input signals in various ways, all of which diminished the quality of the output signal. Electronic enhancements in our cars have proliferated in part because of this consumer reports checklist approach to evaluating cars, which has had the effect of diminishing the relative importance of a car that does basic things well (like, to pick the example that brought me to BMW in the first place, braking).
Financial incentives car manufacturers offered to dealers to sell cars with more and more options also contributed to this trend. Consumer who were enticed by dealers to buy heavily optioned cars responded to consumer surveys that the options were important so as to justify their spending decision after the fact. A year later, most of the highly sought after options went unused.
Watching these trends unfold, it is not difficult to understand why our youth are not passionate about automobiles.