Is the tech industry turning free love SF into a wealth-driven caste system?

http://www.kqed.org/a/forum/R201209250900
http://www.modernluxury.com/san-francisco/story/how-much-tech-can-one-city-take

This topic is quite inflammatory, but just thought I'd put it out there (I don't necessarily agree with the whole argument, and of generalizing a whole industry, but it's better than discussing reality TV!). I guess this is basically the same story as what Wall St. did to NYC. Of course the tech booms brought a lot of money and non-tech jobs to the Bay, but with some costs. Some of the guest's points:

- SF is giving preferential tax treatment to some tech firms, even though other valuable industries could use the lift
- The demand for high-paying tech jobs is driving up rent and other costs for millions of others not employed in tech (and even $100K engineers have to have roommates and can't afford a car)
- Tekkies exists in a "cocoon", as they are just working all the time, are often immigrants to SF, and therefore do not show much civic engagement with the "real SF"
- Despite some high-profile donations from super-rich execs who barely felt it, tech people are generally "selfish" and aren't giving back to the communities that enabled their careers (there is a popular trend of hipster, self-absorbed tekkie libertarianism)
-  "The unique urban features that have made San Francisco so appealing to a new generation of digital workers—its artistic ferment, its social diversity, its trailblazing progressive consciousness—are deteriorating, driven out of the city by the tech boom itself, and the rising real estate prices that go with it." - though it's unclear how much prices would have risen and culture would have changed anyway (ask the black people that used to live in SF before gentrification).
- Really, how much is the next social gaming or shopping app startup contributing to society's benefit - and is that worth the loss of SF uniqueness (it would be a shame if the city becomes just another sterile commercial zone)?

But regardless, it is against the American and San Franciscan democratic, pluralistic spirit to have an elite class of tekkies and investors dominating valuable metro areas, with the rest of the people serving as their supporting underclass but unable to afford to live within 50 miles of their jobs. That is a major social, economic, and moral problem - and one industry is not fully to blame of course.