The ever-changing euphemistic language seems to me like mostly just a new way to be a hipster. The new vocabulary is a shibboleth to distinguish people who got the right sort of education from the right sort of places. Your knowledge of all the proper euphemisms to use sets you apart from the uneducated rubes.

The problem is, it sets you apart from the people you're allegedly trying to help, given that the marginalized are rarely those who got an elite education at an elite institution. This is how Republicans, a coalition of rich tax-avoiders and poorer people resenting the contempt of the elites, stay in power. And their political program - slashing benefits, cutting social services - hurts marginalized people the most.

By creating a way to be a "good person" that only the most hip and educated people can follow, the language policers are creating a rift between themselves and the people they are trying to help, preventing a political coalition from forming that would be able to pass helpful policies.