It's the reverse in a lot of places. It's common in the Baltimore / Washington area to base salaries on years of experience, education level, and industry certifications. I've applied for jobs where the first question HR asks is do you have at least 10 years of experience. These jobs pay as good or better in absolute $ terms than any salary range I've ever seen for engineers in the valley and if you look at it from a cost of living adjusted value the valley pays a lot less.
My two cents is that preferring young employees has a lot to do with the fact that they will work for a lot less money and put up with housing situations that more mature people wouldn't tolerate.
There was a recent article in the Chicago Tribune about bringing dogs to work with the following quote:
"What we're trying to create here, it's lofty, open, we bring in lunch, we hire younger people. Part of creating the vibe is not just the space but the amenities. Bring in your dog."
The "rest of the world" is probably happy to ride the hype the SF crowd are cooking. I know a bunch of companies here, who use python not because its a good choice, but its "hip" and they can appear cool and sophisticated.
Huge difference. CA companies and investors (e.g. YC) specifically require your age to the interviewers. Using YC as an example, many interviewers are happy to publicly boast about using age as primary factor - I can link to to some comments written here on HN.
In some other places, e.g. NYC, this is all generally believed to be highly legally-risky and no respectable employer would ever consider doing it.