Personally, I think ageism in the industry is great. Let my competitors ignore the large pool of experienced engineers out there, and hire some young kid who is "cheaper". While he's fixing his design for the tenth time, I'll pay that expense old dinosaur to do something boring, like get it right the first time.
Last team I built, that was exactly how I hired. My team of 5, all 35+, could run circles around your typical team of 20. Only downside was it was sometimes hard to get them to try new things.
Why would I want to try something new when Perl and MySQL running on Solaris and Apache gets the job done so well? Just kidding :). As I get older, I do find it easier to rationalize using the older, mature thing over a newer, less tested thing.
I'm currently slowly cleaning up the mess created by older developers because they were inexperienced in mobile development and under the startup pressure gun. I'm understanding what their situation was and they are not bad developers. Old != Great. All of these heuristics just help you save energy in evaluating people, you need to evaluate people properly in the first place.
