Regarding it's a property of the places I'm interviewing at.. .. there's a startup boom in NYC. And I think startups prefer young, dynamic types on the cheap?

Regarding it's a property of the places I'm interviewing at.. .. there's a startup boom in NYC. And I think startups prefer young, dynamic types on the cheap? A buddy of mine from California says this is the Silicon Valley mindset creeping in. I'm not so sure, but there is something about startups and not hiring too many older folks.