The theoretical fruits of deliberate oversimplification through idealization are not to be denied... Reality in all its messy particularity is too complicated to theorize about, taken straight. The issue is, rather (since every idealization is a strategic choice), which idealizations might really shed some light... which will just land us... diverting fairy tales.
First, it is a commitment to particularism, to giving priority to the specificity of particulars, not to abstractions and generalities that divert our attention away from concrete realities. Idealizations tend to be partial and distorting, obscuring the heterogeneity and complexity of actual experiences and concrete practices, which is why they do not provide an adequate standpoint for the diagnosis of social problems and injustices.
In rational inquiry, we idealize to selected domains in such a way (we hope) as to permit us to discover crucial features of the world. Data and observations, in the sciences, have an instrumental character. They are of no particular interest in themselves, but only insofar as they constitute evidence that permits one to determine fundamental features of the real world, within a course of inquiry that is invariably undertaken under sharp idealizations, often implicit and simply common understanding, but always present.