Natural hair is political in a way your examples aren't. In fact, your reaction is a perfect example of what the original article is talking about: people projecting their own experiences onto the rest of the world and thus making wrong assumptions about what will succeed or fail. In this case, those assumptions are both gendered and racial in nature: this is a profitable start up that most white men would never have thought to create.
Still, the business as it's presented is destined to fail unless they have a broader-based pivot in the works.
It's not that you are racist, and I didn't say you were. However, the reason you don't understand that "natural hair" is a unique identity within the African-American community speaks to your lack of experience, and that lack of experience probably has something to do with the culture you come from. That doesn't make you racist, that makes you ignorant, which is fine as long as you don't assert that your ignorance is more correct that statistics that contradict you.
This is why it matters that diverse people build businesses: there are people out there who's needs I couldn't predict because I don't have the experience to know what they are. It is incredibly arrogant, however, to assume that because something isn't a part of your personal experience it either doesn't exist, doesn't matter or is doomed to failure.
What you call "common" sense is a collective set of prejudices you rely on as a sort of defense, or shortcut, against having to constantly question your base assumptions. The strength of common sense is not that it's predictive, but that you can make baseless assertions about the world and expect them to be accepted unquestioningly, so long as you are speaking to an audience whose own core beliefs will be comforted and affirmed by your statements. By forwarding common sense as justification enough for unsubstantiated assertions, you're basically pandering.
But, if we strip away your crutch for a moment and ask another set of questions, the point of this article becomes obvious -- because you have illustrated it with (probably unintentional) hilarity. Instead of asking (rhetorically, because you assume that everyone shares your assumptions) why this wouldn't flop, let's ask:
* Why should anyone believe you know anything about what makes a successful investment and what the predictors of a successful exit are?
* Do you know anything about the curly/wavy-haired segment?
* Have you ever invested $1.4M (or even $14k) to the effect of generating ROI of whole multiples?
* Have you ever sold any beauty or hair-care products?
Who are you, and what is the evidence that you know anything about what you're talking about?
At the end of the day, columns like this one in NY Mag thrive on people like you, whose reliance on unquestioned assumptions allow them to circulate bullshit like it's truth.
I'm certainly not in any position to make intelligent comments about this market, but I'd be wary of dismissing it because it's something that's not important to you personally. Fashion is another example of a market that many people here don't care about at all but that generates quite a lot of money.
It does not address exactly what a social network would accomplish for the consumer beyond acting as a conduit for advertising. That's where the issue is.
Every website is a social network in its press release. Journalists will repeat those descriptions. Don't fight it, you'll lose your mind.
Anyway, many social networks attempt meet pain points. Women with naturally curly hair deal with alot of issues. Lack of products, good stylists, societal issues (e.g., "is curly hair professional?"). It's the kind of thing you probably don't think about unless you have curly hair. Lots of bonding among curly-haired women is already occurring online. A central network is a great idea--I'm thinking it will be really popular. It's part of The Long Tail.
I'm not interested in debating the validity of whether there is market for this group of people. Just that the article in question does little to support the claim. It argues that a lot of people have curly hair and buy curly-hair products. It says nothing about why these people want to congregate online in a specific social network.
In fact, your 2-sentence paragraph said more than the entire article.
Anyway, ideas are cheap. This is a business and it has been funded and well-positioned to control their exit.