There's a saying in academia that people study what they don't understand: economists don't know how to do business; psychologists are all neurotic; linguists communicate poorly; anthropologists tend to be misfits or outsiders; and so on. Case in point: my first year of grad school I went to a anthro student's house party and was one of three people, out of about 25, who brought beer. That party didn't last long. I wondered, if they can figure out that norm, after 22 plus years of enculturation in American society, how well they'd do in some village picking up on the cultural norms in just a year or two. That explains the contemporary dominance of theory over data I guess.