While it might be a constant joke that economists and humans don’t think in the same way, consider this description of economists’ views of unions:
Most economists, for instance, see the weakening of trade unions in the U.S. and other Western nations in the past few decades as a good thing, because unions’ monopoly power over wages impairs companies’ ability to adapt to the demands of the market. As Acemoglu and Robinson point out, however, unions do a lot more than influence the supply and cost of labor. In particular, they have historically played a prominent role in creating and supporting democracy, in limiting the political power of corporations, and in mitigating income inequality.
I’m always wary of “most”, but my impression is that, at least as communicated in the popular media, this isn’t so far off the mark. But there would quite a few people who would place far more importance on limiting corporate power and on lessening income inequality (including some economists) than concerns about inflexible wages (especially since some people would benefit themselves from those inflexible wages). By using market clearing as the criterion for judging labor policy (as opposed to other criteria), one is able to make certain policies appear apolitical and ‘common sensical’, when they are incredibly value-laden.
Mind you, economists certainly isn’t the only discipline that does this. In medicine, the emphasis has traditionally been focused on prolonging life no matter how little time is gained, even if it leads to utterly miserable quality of life for that extra time. In this case, however, the conflict between normative propositions (what ought to be) is generally acknowledged (in discussion, if not in practice). The social sciences are worth defending, but only if they’re willing to admit their biases.