It is useful and important - just not to hackers.
If you look at the range of MBTI personality types (not that this is hard evidence), there's plenty of people who don't view the world in terms of focus, efficiency, and usefulness. In fact, one of the common differences in the J/P split is that P's like wandering about, being irresponsible, and having things constantly changing around them.
The social usefulness comes from the F/T split. To those who are thinkers, the people aspect is often belittled because to them, there is no pleasure gained from communicating with people (but, LISP... now that is a joy to work with!!!). However, to the F types, talking to people is very pleasant and comfortable - much more than writing code in a structured, logical programming language would ever be.
Wikipedia says that FP's count for 30% of the population, and FJ's, another 30%. Compare that to TP's or TJs (16%, 24%), and social browse captures a majority market space.
Programmers (INTPs and INTJs, mostly), although they are generally more active and enthusiastic customers, account for < 10% of the population. And they are right in that social apps aren't useful or important to them. However, they're a clear minority in terms of user base, and they're picky, disgruntled, hard to keep, and easy to offend.
SocialBrowse (and all social apps) may not have value to them, but it definitely has value to the majority of the world. Now, the key is getting off tech blogs and into real world marketing, guys.