The fundamental flaw with this position is that "Jew" doesn't have the historical context of being used to denigrate a race, whereas "Jap" and "Paki" do.
See I think this varies in geography. MY people haven't had a history of using those terms to the degree others might. Other races moreso, but not particularly these. So the associations are different. But as long as your country is running the world, things are as you say they are.