What are the pros and cons of using postmodern approaches with people from diverse populations?

Postmodern approaches stem from the premise that the (meta)narrative of modernity is not only totalizing and universalizing, but that the universal values and concepts derive from the Enlightenment subject - who is male, straight, white, and propertied. Thus, by universalizing a particular subject, those who don't already fit the mold - or can't be disciplined into an effective disguise - are effectively excluded, marginalized, or pathologized. Therefore postmodern approaches are fruitful for working with diverse populations - as difference is not only recognized as legitimate but is celebrated. However, there are two critiques leveled against such approaches. The first critique is that dismissing any and all forms of universal values can easily regress into an amoral relativism, whereby the search for any commonalities devolves into intensifying antagonisms with no organizing principle for resolution. The second critique stems from the hypocrisy of celebrating difference when postmodernism itself emerges from the very particular elite context of the Western academy during the Post-Fordist era (e.g. late capitalism, neoliberalism, etc), and therefore (just like modernism) postmodernism represents the particularities of the subjects that made the concept possible while simultaneously placing such origins under erasure.