The problem is not just one of income disparity (software engineers, CEOs, and other tech employees receiving orders of magnitude more income than workers in other fields), although that issue is significant, it's one of outflow. Because the Silicon Valley economy has so many highly-paid employees in tech and related fields (e.g., IP lawyers), prices for all goods rise. The well-to-do don't feel those price rises especially, but the people barely scraping by definitely do. Housing tops the list by a country mile, but the issue with housing is not just one of income disparity (demand), it's also a question of supply. San Francisco proper exists within a 49 square mile grid, and there's a limit to how much it even can be built up, to say nothing of all the issues caused by anti-growth crusaders. South of San Francisco, however, dwellers on the Peninsula and in the South Bay have made themselves a big part of the problem. From South San Francisco to San Jose, try finding more than a handful of residential buildings outside of downtown San Jose that are taller than three stories. Housing in and for the Valley has been artificially constrained by growth limits, while demand continues to grow, both in terms of population and income, meaning that there's no choice but for housing costs to spiral ever upward. It's all well and good to claim that someone should build more housing (and more housing is constantly being built), but the anti-growth laws on the books throughout the Bay Area are ruinous for the poor.
If the tech CEOs really want to do something helpful, they can lean on the mayors and city councils throughout the Bay Area to remove growth limits and fund improved public transportation. Rather than contributing handouts, they can contribute political will and financial capital towards fixing the one dominant issue that makes the Bay Area so expensive. They can also pay their damn taxes.