http://www.thetruthaboutcars.com/2013/10/generation-why-no-job-no-money-no-car/
Be sure to read the two links from DCAutoGeek and the IIHS study as well. While the modern trend of younger folks not driving is noticable, I have always thought that ECONOMICS (purchase/fuel/maintenance/insurance) of auto ownership has far more to do with this event than improvement of technology and telecommunications.
Personally, I find the complexity and expense of cars also combines with today's modern society of not being able to do things yourself: but for automotive enthusiasts, we live in a CostCo/WalMart-throw-it-away, instant-gratification society that prefers "the new" far more than something you make yourself, or purchase used and keep it running. The expectation that everyone should just buy/finance/lease a new car - and this is a message from parents, too! - trickles down to a society of dependent consumerism.
/rant