Well Mike, I know there is an element of truth there, but it's far from as wide spread as you suggest. I have met and known people who couldn't find employment in their chosen fields as they got older, but for the most part, the problem wasn't their age, it was that the utility of their skill sets withered.

I'm in my mid sixties, work in IT, and have had four different jobs in the last twenty years, with severances covering the gaps in income. Most of my long term acquaintances and colleagues who want to be employed are. They (and I) thrive on learning new stuff, so we always have something of value to offer employers.