"So what advantage does a 60-year-old .NET programmer have over a 27-year-old .NET programmer when they both have, at most, 5 years of experience doing .NET programming? Absolutely none."
Umm, I would say that 40 years of experience building software applications is a pretty huge advantage. I've been writing iPhone apps longer than most of the older guys I work with, but that doesn't mean that I know more about development than they do.
Languages and technologies may be temporary knowledge capital, but they're also one of the least valuable things a good developer will have.
As far as prestige and foreignization? It's amazing how much things can change in 5 years. Programming is (sorta) becoming cool thanks to things like The Social Network. 2/3 major operating systems are developer almost exclusively in the United States. All major programming languages are in English. Software development isn't going anywhere in the US.