This is such a weird comment. If transit systems arent built around people's housing and employment, its useless. San Francisco is a huge city, with a significant population that commutes south as well. Even if the transit was originally made for people commuting into SF, it clearly isnt what is needed the most now. Downtown SF office space has significant vacancies, and I would guess there is a similar number of workers commuting south as there are commuting north.

Caltrain's current ridership (very poor) demonstrates the need to change the connecting systems so it is popular again. The idea of having rapid busses connecting to the caltrain stops (especially 22nd and bayshore stations) is hardly a massive thing, and could significantly improve transit across the Bay.

Building robust transit between SF and San Mateo is good for everyone, its not selfishness.