Adaptation important to PCMs?

Is "correcting for patterns of maladaptation in related species" tantamount to ruling out the influence of non-adaptive traits on the observed phylogenetic structure? I may be misunderstanding, but this seems to be excluding the possibility that a trait evolved NOT through direct selection. i.e., A trait could also show up in a population because it is linked to a gene that IS under selection, but not for the trait in question (pleiotropy) -- right?

I guess I'm confused about why the adaptiveness / maladaptiveness of a trait is important to the use of comparative methods. A given trait could go from adaptive to nonadaptive in an afternoon given an appropriately sized environmental change. I thought the main importance of PCMs is to account for evolutionary relatedness in species comparisons, not necessarily the role of adaptation..?

Most of the above is directed toward Hansen et al. 2008