If you're over 50 and in the interview, it's obvious that you're up to date (that doesn't mean knowing the API of the latest trendy bullshit, but it does mean you don't think SVN is new and scary), and you have the skills of someone with 25+ years of experience, not only will you get an offer before you have time to get in your car, in any of the tech hubs (not just SV and the west coast), the conversation will start at over 300k total comp and you'll be able to milk them up from there.
The problem is that there just wasn't that many software engineers back then (compared to today), and the vast majority jumped ship when the dot com bubble crashed. Of what's left, a large section are scared of SQL as something too technical, or are too scared of new tech to learn them enough to explain why we shouldn't use them, from experience.
The rest though (which leaves very very few)? You can't hire them because they're never on the job market.
As the huge influx of engineer gets older, it's a problem that will go away. Eventually there will be more older engineers than younger ones, and we can go back to the good old days where no one could get a job without 10 years of experience in a technology that's 5 years old.