I think the author's point is that this sort of usage is only actually feasible with a very narrow demographic, in one or two places in the country -- maybe New York, Boston and San Francisco. Elsewhere, the chance that there would be even two people in a given bar or club running that app and looking for new friends at the same time is basically zero point zero.

Besides that, in the introductions world, "meeting new friends" is marketing-speak for meeting people to date, or more precisely, to hook up with. And, I can imagine, as the author does, that women would be pretty squeamish about getting involved with a service that announces their presence in a particular bar and invites people to meet them.

In any case, Loopt has this service, or at any rate did at one point -- in one of their iterations, they cordoned it off into its own application (Loopt Mix). I turned it on briefly once, to see what it would do, and to be honest, it was pretty creepy, a lot like the parts of Craigslist that have been shut down ...