If your business makes any decisions, like "how do we capture this market," or "what sort of features should we add," or "how should this thing work," then you are embarking on a truth-seeking endeavor.
Unless your product aims to solve a problem that only affects white guys in the city (which, to be fair, is certainly a non-negligible number of products), then you're going to have a hard time expanding your base beyond white guys in the city if your team consists of only white guys in the city.
I think a white man can make a product for black women, and I think a black woman can make products for white men. For me, it's more about acknowledging that the world exists outside of white men in the city and less about making sure your team is made up of every racial and socio-economic variable you aim to market to.
As Vezzy-Fnord points out, a single individual is able to empathize with other types of people, but that empathy is finite, and also, empathy does not equal understanding.
It turns out that "white guys" are not a homogenous group. In fact, chances are that white guys from (e.g.) Finland, Serbia and Nebraska will have little in common besides their skin color and sex. Their opinions and worldviews will differ greatly.
Diversity of opinion is just as important, if not more so. Sure, on the outside everyone looks like a pasty-faced white dude, but jumping to conclusions based solely on that, is... misguided, to put it euphemistically.
I'm not saying we can't benefit from having a wide variety of phenotypes as well, after all different phenotypes equal different experiences. But not every white guy is a Bay Area caricature.
Maybe "we" should feel guilty about socially engineering something that is proven to make people unhappy. Ironically, the happiness index in women is down in Western societies whereas the same measure for men, is up! And we can hardly argue that women are treated as less equal than they were in the 70s.
People have a knee jerk reaction and say "oh yeah, that's because women have to do even more work now" where that isn't actually the case. Married women with traditional gender roles are actually happier than their married and equal counterparts.
Now, I know I'm not providing any statistics or references but I would urge you to be on the lookout. They show up quite regularly and are easy to find once you are open to the concept. One good place to start is "Brainwash", a "documentary" by a comedian that actually resulted in a loss of funds to a gender studies institute.
All this being said, I do not think a single one of us would say that a woman should not be encouraged to be a programmer. But to deny the joy that a woman can get from being a "traditional" mother as well as a programmer is unfair to an entire gender and unfairly creates a generation of latchkey children. I do not know a single mother or father who says "Yeah, I wish I spent less time with my kids."