Look at this picture.
In late July, 1909, we were still trying to cross the English Channel by air. Sixty years and one day later, we were on our way to the moon.
Forty years after that, and what have we done? Dawdle long enough to probably let the Chinese beat us back to the moon, is what, not to mention losing the national sense of drive and ambition that made this country what it was during the 20th Century.
That sort of thing contributes to the background of the old TNG Space Hippies idea, by the way.