Smart people are leaving the San Francisco Bay Area because of its hostility to free and open speech. That’s the view of Sam Altman, a prominent figure in the tech world, who published a controversial essay on Wednesday decrying the region’s allegedly oppressive social climate.
Altman, who is the head of elite Y Combinator startup accelerator program, is already facing a backlash from others in the tech industry over the essay and its claim that the Bay Area has become too “toxic” for those in fields like genetic engineering. Other incendiary passages include:
I felt more comfortable discussing controversial ideas in Beijing than in San Francisco. I didn’t feel completely comfortable—this was China, after all—just more comfortable than at home.
That showed me just how bad things have become, and how much things have changed since I first got started here in 2005. [..]
This is uncomfortable, but it’s possible we have to allow people to say disparaging things about gay people if we want them to be able to say novel things about physics. [1] Of course we can and should say that ideas are mistaken, but we can’t just call the person a heretic. We need to debate the actual idea.
Much of the essay is more measured, calling for more vigorous public debate, and noting that geniuses like Isaac Newton often held crackpot ideas like alchemy even as they developed brilliant ones. It concludes by saying “political correctness often comes from a good place…but too often it ends up being used as a club,” and by suggesting San Francisco would have stifled the anonymous founder of bitcoin. (While Altman claims he knows innovators who left the city over its culture, he doesn’t provide names).
Get Data Sheet, Fortune’s technology newsletter.
Altman’s essay quickly attracted a fierce response on social media. Twitter users assailed him as insensitive and embodying a negative stereotype of tech industry absorption:
Sam, you’re super rich and have no real boss, you can say anything. Maybe your “controversial” opinions are just bad https://t.co/asttGgnry5
— Jared McKiernan (@jaredmckiernan) December 14, 2017
https://twitter.com/gardaud/status/941415723275927552
https://twitter.com/SarahNEmerson/status/941383827007488000
Some, however, agreed that San Francisco’s embrace of political correctness has gone too far and become an impediment to the free exchange of ideas. Others suggested the backlash to Altman’s essay was proving his point:
Clearly we can't allow discussion about whether we should allow debate on a topic that's offensive.@sama claimed "to get the really good ideas, we need to tolerate really bad and wacky ideas too." But it seems we can't debate that without pillorying him.https://t.co/WA4ULxnGmihttps://t.co/hzvdRogfFW
— David Manheim (@davidmanheim) December 14, 2017
More broadly, the uproar over Altman’s essay coincides with a civil war of sorts among Silicon Valley’s tech community. One side claims the industry hasn’t done enough to address its reputation for sexism and social insensitivity, while the other argues the reformers have become censorious zealots.
