How much of human activity is just signalling, posturing, and status jockeying with no purpose I would consider practical. To the point where those behaviours seep into contexts where they're obviously unproductive, like discussions on pseudonymous Internet forums.
Robin Hanson has some extensive descriptions[1] of what I mean, with the crucial insight that "X is not about Y"[2], and that rationalization may be the original, evolutionary purpose of rational thinking rather than its perversion[3]. He even offers remedies[4] if you consider it a problem.
http://alaindebotton.com/status/