Compared to LA, Houston, perhaps. Compared to New York or Chicago? No. It's remarkably poor. The fact that BART didn't reach SFO until 2006? or so is more or less all you have to say.
EDIT: Although, to be fair, the Valley and San Jose are way too low density to support a decent transit infrastructure. San Francisco's MUNI disaster is a problem of a different order.
Keep in mind that NYC and Chicago have the unfair advantage of having most of their rail infrastructure already built during the private rail transportation boom from the 1800's to WWII. Most of the subways and rail transit in these regions are still running on lines that were built between 70 and 120 years ago. The west coast has to rely on clumsy governments and public financing to move anything forward for all of its transit infrastructure, which is why it takes so painfully long to get it right
SF also had leading edge rail transport during those times as well, which was later abandoned for the most part.
There is a significantly different topography in the bay that greatly complexifies rail projects. Effective rail coverage on a large grid is not possible due to water and hill issues.
With regards to density, San Jose has a density of 5,256 people per square mile. In contrast, Denver (which has an awesome train/bus system) has a density of 3,698 people per square mile.
If low density is why San Jose can't support a decent transit infrastructure, then how can Denver do it with even less density?
Just my guess, as a Denver-area resident... Metro Denver has several areas with very high concentrations of office space and jobs (Downtown, DTC, Broomfield/Interlocken, Boulder, etc.). Also, the residential density (even within Denver proper) varies a great deal. The lower-density areas probably don't have great bus service. (The residential density also seems to be increasing, with a lot of infill development projects.) It helps that the Denver area is known for having strong regional cooperation with a single transit authority, instead of the crazy mix of poorly connected services in Silicon Valley.
Silicon Valley office space seems to be a little more spread out. When I was visiting a client in Santa Clara last year, I had to walk almost two miles to get to a light rail station to go have a nice dinner in downtown Mountain View. (And there were no buses available to cover that distance -- at least not that Google Transit knew about.)
(Disclaimer: My experience with San Jose is mostly limited to the airport area, and the Silicon Valley suburbs to the north.)
I live in Denver and second that the light rail / bus system is pretty awesome. It should be even better with light rail expansions coming in the next year or so.
I live in Denver too and I haven't driven to work in 6 years. Instead of driving myself, I read, listen to music and chill out. I also don't worry about traffic, weather, or really much at all. It's great for drinking after work too.
I share your enthusiasm for the upcoming expansions, in particular the line to the Airport. The train is one of the big perks of living in Denver. It's awesome and only getting better.
Silicon Valley might be too low density to support transit inside the city, but is it too low density to support good commuter rail back and forth with SF? I don't think Silicon Valley is less dense than say Westchester County, NY, yet the latter manages to support a pretty great commuter rail network with three lines and 300,000 daily riders within a commuting region of maybe two million people.
Commuter rail cannot exist in a vacuum without local transit. Metro North gets you into Grand Central, but most people don't work right on top of Grand Central - a supplementary transit system is necessary to get people to their actual endpoints.
The CalTrain, which is the closest SF Bay equivalent to MTA commuter trains, stops in San Francisco, but far from local mass transit connections (either MUNI light rail or BART), to the point where there is an industry for private shuttles. This is a significant barrier to the adoption of commuter rail for people who work in the city but want to live further out.
Similarly, once in the Peninsula or South Bay, the CalTrain is often not near a mass transportation connection. Some of the major tech firms are located "near" CalTrain stops, but nearness is often at automobile-scale, as opposed to walking or cycling scale.
You need a pretty-damn-good local transit solution to support commuter networks.
The problem is that the Valley is a host of municipalities of differing sizes, with San Jose at the bottom end. It doesn't really go as far north as San Francisco (yet). Westchester works as it does because it's largely feeding into New York's superb infrastructure -- there's no comparable network (or city of comparable size) on the Peninsula. There are a lot of people commuting from e.g. Belmont to Cupertino or Mountain View to Palo Alto.
Despite the limited life experience of some Chicagoans and New Yorkers who have not left their enclaves and thus have come to think they are the center of the world, these cities are not actually "most of the rest of the country", as I said.
Perhaps their citizens can not emerge from their bubbles far enough to believe it, but it's true.
The bay has regular bus service, sidewalks and bike lanes. Also trains. If you drive, you can do so from one place to another and find a parking place.
As someone who doesn't like to deal with cars, when I lived there it was very nice compared to the rest of the country, at least the 30 or so cities and towns I have lived in and the few hundred that I have stayed in for more than a few days, most of which it was extremely troublesome to get about without a car, and unlike San Francisco.
This is a discussion about public transit, why was the ad hominem attack necessary, or the blatant straw-man stereotyping? Has anyone here indicated that they live in NYC/Chicago and haven't been elsewhere?
FWIW, I've lived in 9 cities in 3 countries across 2 continents. This includes San Francisco, and I can tell you, I've lived in metro areas substantially smaller than the SFBay and had better transit. There are many places in the US substantially worse, but there are also many others with a similar density profile or population size that are substantially better.
EDIT: Although, to be fair, the Valley and San Jose are way too low density to support a decent transit infrastructure. San Francisco's MUNI disaster is a problem of a different order.