No matter what you think about climate change, that subhead is a rookie mistake and a false dichotomy: The private companies are taxpayers.
Yes, in the sense that you would still nominally be a taxpayer if you had ways to pay $1-$5 tax per year, while still making $300K.
Also consider that all the workers are also tax payers and they want the company to continue existing, their taxes would also go towards protecting the bay. Their tax dollars wouldn't exist in California if those tech companies weren't there.
In fact, it's from places all over the world, significantly poorer places, where the money would stretch even further.
You're making it sound even worse.
Edit: The main point is that nobody can say that San Francisco has less money with those tech companies operating there than they would if those tech companies left. They are among the richest places on earth and should easily be afford any measures that can be afforded anywhere.