Recruiters spamming you is not a correlative metric for companies hiring you.
SV is worse than other locations, but even the midwest company I work for (I'm also over 40) much prefers to hire people straight out of college. They're cheaper, willing to work longer hours, and easily molded into an image the company wants.
EDIT: To provide a small anecdote about recruiters - I regularly get Google and Facebook recruiters hitting me up on LinkedIn, even though I know I would never be hired by them. I don't live in a state where they have an office, have no plans to move, and don't meet some of their publicly announced filters. I'm up front about this to the recruiters, yet I still get spam from them.