The key point isn't whether the "quality of relationships" is different between regular phones, cell phones, texting, or the good old fashioned face-to-face conversation. What the LW is complaining about is somebody going out with the group, but then deciding they'd rather be texting people who aren't there instead of interacting with those who are. It'd be the exact same problem if they were yammering on the cell phone for the entire night.

I doubt any of the posters above would go for their friends telling them they were perfectly capable of reading a book and talking to them at the same time; yet they seem to believe they themselves can carry on meaningful conversations while texting. These are likely the same people who think they're the only ones on the road who can talk on the phone and not have their driving suffer. It's always a problem for "the other guy."