The fact is that insecure groups will ALWAYS be offended by any name they feel is "given" to them. Best example is that "negro" or "colored" was once accepted. Then there was a demand "Say it aloud, I'm Black and I'm proud!" Then it was decided that black was pejorative, to be replaced by "African American." Now I wonder the origin of the word "Africa?"
One thing I can guarantee you, in 20 years the term "African American" will be considered pejorative, as whites are now using it more and more. My guess is the next stop will be just "African." Interestingly, "people of color" (acceptable) sounds awfully close to "colored" which is no longer acceptable. The problem is seeking an identity but not wanting to be labeled.