Armchair psychology? No, I've made many friends and acquaintances, both online and in real life. The ones that bubble around posting online heavily, have developed antisocial tendencies that were reinforced through social exclusion. A self-fulfilling prophecy. I know this, because I know those people well and because I was there at one point in my life as well.
Neither is it condescension. Perhaps I may have been in-exact and may have offended some that do post online very regularly, but there must be a distinction between what they consider "regularly" and what I consider "heavily." Heavily, in my observation, is someone that puts aside a significant amount of time, usually involuntarily, to do nothing but interact with online communities for the sole purpose of social interaction. No value judgements were made either, but those characteristics are common among the aforementioned group.
I won't address your hypothesis, because I'm not here to argue.