I go out of my way to hire older devs that are eschewed by typical Bay Area startups. I can get a seasoned pro with a solid background in C - and other more trendy languages - for about the same price of a 3-years-working-experience "senior dev" who likely was battlefield commissioned into the role at their last startup.
The typical solid dev can only put in 4, maybe 5-6 hours of actual good coding a day. If you know how to run a tight org - and not a sweatshop of 20-year olds pulling 16 hour days where only maybe 2-3 hours are actual programming time - then older devs are a fantastic bargain. Plus, when it comes time to architect something complex, I have found older devs typically create more simple and elegant solutions just because they have been exposed to more.
Of course, I do run into the occasional stuck-in-the-mud older dev who is very slow to adapt to current trends and wants everyone else to get off their lawn. That has been a rare exception to my overall experience and I don't think it should be used to stereotype the older devs as a group.