Twitter proved this week a point that I have long been making: that Silicon Valley is a boys’ club—a fraternity of the worst kind—stacking the deck against women, overlooking blacks and Hispanics, and providing unfair advantage to an elite, connected, few who have learnt the Valley’s rules of engagement and mastered them.

My spat last weekend with Twitter CEO Dick Costolo also shows the extent of the problem.

New York Times reporter Claire Miller had called me a couple of days earlier to discuss an article she was writing about Twitter’s IPO. She’d asked whether I thought it strange that Twitter had an all-male board, almost-all-male management team, and all-male investor group. I thought this was outrageous given that more women use social media than men; that African-Americans are one of Twitter’s fastest-growing demographic groups; and that the company is asking the public to invest a billion dollars in it—and make Twitter executives and investors worth billions. What I said to Miller was that the elite arrogance of the Silicon Valley mafia, the Twitter mafia, is male chauvinistic thinking; how dare they think they could get away with this?

After all, as I later explained on Bloomberg TV, though it is okay to have a board that is a boys club when you are a private company, when you go public, you can’t act irresponsibly like this. The duty of a board is to look after the interests of all shareholders and maximize the company’s value. Having women on boards produces better outcomes. Companies with the highest proportions of women board directors outperform those with the lowest proportions by 53%. They have a 42% higher return on sales and 66% higher return on invested capital.

I knew that Miller’s article and my comments would not go over well with the Twitter board. But I had no idea that I would be attacked personally in the way I was. Costolo tweeted: “Vivek Wadhwa is the Carrot Top of academic sources.” (Carrot Top is a very successful comedian whom he had mentioned disparagingly.) In follow-up conversations on Twitter, Costolo continued to hit below the belt rather than address the problem that the article raised.

So I wrote about this in TechCrunch (reprinted at WRALTechWire{[/a}}and the Wall Street Journal. I said in the Journal that Costolo’s comments were inappropriate and that he owes me a formal apology, but I didn’t for a moment think that he is overtly sexist or that he deliberately discriminates. I said he was reflecting a behavior common in Silicon Valley, where power brokers proudly tout their “pattern recognition” capabilities. They believe they know a successful entrepreneur, engineer, or business executive when they see one. Sadly, the pattern is always a Mark Zuckerberg, Marc Andreessen, JeffBezos—or themselves: nerdy white males.

I said that, to me, pattern recognition is a code name for sexism and racism. It must end. It may have been okay when the tech industry was in its infancy and companies such as Twitter didn’t get the national attention they do. But they can’t get away with it in this day and age.

So far there has been no apology and no press release announcing that the company will be more sensitive to its ethical, financial, and moral obligations. This is really disappointing.

I have been very harsh in my comments about Twitter management. But Twitter isn’t alone—and sadly it may be better than most companies in its class. All of these companies need to get beyond their exclusionary boys’-club culture and diversify—for their own sakes. Corporate culture is built from the top down. Employees embrace the ethics and values of their leaders. You simply can’t have one set of standards for management and another for staff. It comes from the board—down.

You see the problem manifest itself at tech conferences—such as the recent TechCrunch Disrupt, where two teams made lewd sexual comments and gestures on stage. And within tech companies, where there is often an insensitivity to the issues of race and gender. Note the disgusting poster that was placed in the womens bathroom at Twitter.

By leaving out women and minorities, we are limiting economic growth and innovation. We are doing a social injustice. This must change.

You can follow me on…umm…Twitter: @wadhwa and find my other articles on my website:

(C) Vivek Wadhwa