I haven't thought cultural imperialism was a made-up concept since I watched a terrifiying documentary on the lives of white South African homeowners and their South African household servants (wish I could remember the name, but it's 1:30 am here). "Cultural Imperalism" is a created term, as many cultural studies terms and/or critical terms are by necessity, but it's important to be precise about the term vs. the concept, which I think(?) you are speaking of here.