This is a fascinating topic and the results of the OP's anecdotal experiment are certainly indicative of a growing problem.
Personally, I find it ironic that in the face of a "communication obsessed" society, people seem to be more distant and evasive towards one another than perhaps any other time in human history. I've noticed this a great deal as I've spent the past few weeks tagging along with my mother while she did her holiday shopping.
I observed people very closely during this time and the majority of them seemed to treat others with utter contempt; as nothing more than an obstacle in their all-great purpose of buying unnecessary shit. Out in the real world, I observed a public that was eerily silent. A stark contrast to what we see online or in the text world.
I think social media sites, as well as the internet as a whole, are responsible for creating this illusion that we are more open to communication than we really are. But the way I see it, we are not obsessed with communication, but rather with the feedback we get from what we type and say.
We are obsessed with the news, obsessed with what is going on in other people's lives. We are obsessed with posting, tweeting and blogging every minute of our own lives. But, very rarely during these pointless, everyday ramblings do we seem interested in the actual exchange of ideas and feelings unless they positively boost our ego and self-esteem.
Perhaps we've reached a point where the only way we can communicate with one another is through a computer or cellphone. Actual face-to-face communication seems to be fading out. At least where people outside of our families and circle of friends is concerned.