Well there must have been an underlying reason why companies would go out of their way to invest in their own transportation system than invest in the one that already exists. Maybe they were met with resistance? What is this resistance?
This sounds a bit like asking why anyone buys a Brita pitcher instead of investing in water & sewage sanitation.
The cost and effort involved in chartering a few buses is pretty minor next to re-tooling the Muni, BART & Caltrain systems. The results are also instantaneous. They need to attract employees now, and not in 5-10 years time.
It's worth noting that a public transit commute between SF and SV can involve up to 3 distinct transportation systems. For instance, when I worked for a startup based in Menlo Park I contended with a trifecta fail-fest of Muni (bus) -> Caltrain -> local shuttle, totaling 2 hours each way.
Also, companies locate in places not remotely near public transit-like Facebook's new campus in Menlo Park, its not remotely near Caltrain. I remember taking the light rail along Java Drive every day for two years, wondering why more companies didn't decide to relocate near public transit, instead of in the outer most parts of suburbia.
