I disagree. I wouldn't be sanguine about it. Previous major waves of technical innovation were lead by well established Americans. Something has changed.
A plausible hypothesis (not that I'm convinced) is that high immigration has driven down wages in technical professions. So native born Americans are less inclined to bother.
I think it's important to point out that two American eras of high growth and prosperity had essentially zero immigration. From 1921 to 1965 immigration was practically nothing. This was a period of extreme American innovation.
Uhm, what? Perhaps in raw numbers, but the world wars drove vast numbers of european intellectuals to the US.
Rather I think Americans dont take tough courses in college - ie science/technology courses. How many computer science (for eg:) MS courses even have Americans enrolled in them?
Americans take it easy in college. Heck, if I'd been born here I'd have done the same. :)
... because an army of H1Bs and green cards have driven down wages and thus the incentive to pursue science & tech careers? Seems at least plausible.
Just like I'd be willing to bet that americans living abroad are overrepresented as entrepreneurs wherever they happen to be living.