It's true, many organizations don't want to hire anyone older than about 40. I've run into it a time or two. In some cases it's deliberate policy. Don't hire senior people because they want too much money, or cost too much in self-insured health care costs. These cases are completely despicable, and you can't sue these companies enough.
In other cases, it's more subtle. I think people want to hire people whose resumes look familiar (like the resume of the hiring manager). If the hiring manager is 32, and learned java and web programming in school, then that's what he thinks is good. If the candidate knows C++ and distributed programming instead, that makes the candidate look unfamiliar and therefore antiquated. It doesn't matter if the candidate faced the same issues as the hiring manager. It doesn't matter if the candidate had to personally solve issues for which the hiring manager was able to use a standard packaged solution. And apparently it doesn't matter if the candidate has solved years of programming problems, giving the candidate the "muscle memory" of the master craftsman. It's all about being familiar to the boss.
Whatever. It is fortunate that a few shops know that senior people are more productive than their trendier peers. The senior engineer who finds such a job can work quietly with his fuddy-duddy peers, turning out great code and laughing at the pomposity of younger developers who won't "get it" until they turn 50 or so.