Id be surprised if teenagers in the 70's could tell you much about the Austro-Hungarian Empire, or if teenagers in the 1900's could tell you much about the war of 1812. I agree that the internet has made access to entertainment easier than ever (obviously), but I think the lack of interest in education in America is alot more complex than that. "Knowledge", in the classical sense, is wisdom imparted on younger generations from the past, or older generations. If you had to pick a specific time when Americans turned on the authority of older generations you could probably say the Vietnam War/Civil Rights era (or maybe even the Korean War...which is the "Forgotten War" for a reason, I think, in an age when access to truth was much more easily censored). If this dude's generation was so knowledgeable of history when they were teenagers, why weren't they protesting the Vietnam War in the early 60's, as opposed to when it was too late? Shouldn't they have been experts in what happened in Korea...especially with no internet to distract them?
And, of course there's value in being wary of the "authority of tradition", but in a culture that has embraced that outlook in such an extreme manner as America, anything that isn't immediately self serving becomes trivial...like being well read, objective in matters of politics, knowledgeable of societal developments, etc.