Yes, it's quite simple: there are many more men in the Bay than women, so women have their pick, and they can afford to raise the bar far higher than $120k.
Also, $120k can be a nice annual salary in much of the US, but doesn't go far in the Bay where median house price is over $1m.
Consider just FAANGs in the Bay. There's probably not enough available single women just for every straight FAANG male employee (who would be making more than $120k/yr).
Anecdotally, I know some women in the Bay, working in areas like recruiting and marketing, who are dating VCs and CEOs exclusively and consider dating "plain engineers" to be beneath them.
Fair or not, your "male SWE making $120K+ a year" has become the "common guy" of the Bay. The number of women is small enough that most of them can aim higher.