I have wondered why the United Negro College Fund, the National Association for the Advancement of Colored People and the US Bureau of Indian Affairs have not updated their names. In other contexts use of those terms is considered inappropriate.
For the first two, because the “brand awareness” is strong, and most people only use the initials anyway. For the third, there’s also the fact that there are quite a few Native Americans who’ve “reclaimed” the word Indian (spelled “NDN” for social media purposes!) and use it among themselves. (Of course, as I’ve said elsewhere, I reject your underlying assumptions and your use of the term “political correctness,” since it ignores the equal hypersensitivity and readiness to take offense at the other end of the political spectrum.)