I can't say for sure, but I'd guess that the turning point was the publication of Edward Said's book "Orientalism". This book (which I haven't read) seems to have taken the West to task for viewing all things oriental as "other", "foreign", "exotic". In other words, not at the same level as Western. I think oriental became a bad word after this.
But do keep in mind that the term "colored" was once OK (witness NAACP). But then that was bad, and you had to say "black". But then that was bad, and you had to say "African American". They keep changing the rules so that what you say is wrong, whatever it is you say.
But do keep in mind that the term "colored" was once OK (witness NAACP). But then that was bad, and you had to say "black". But then that was bad, and you had to say "African American".
Yes, but in addition, between "colored" and "black" was "Afro-American."