to paraphrase mae west, academic has nothing whatsoever to do with such a poor definition. i'm aware of its origin but that's hardly an excuse to continue using a term so lacking logic and precison (the two qualities demanded--by definition, if you will--of anything purporting to be definitive).
So you want me to make up a new word which wouldn't be understood by everybody else because otherwise you won't understand what I am talking about?
Everybody knows what an anti-Semite is.
If I said "anti-Jewite" instead, people wouldn't know that that is really the same as an anti-Semite in newer English.
Plus it doesn't really matter anyway, since a person who hates all (or any) Semites is just as bad as a person who hates Jews only. We could call them "racists" as well, if you like.
it should be replaced by "anti-jew" or expanded to include hostility/prejudice against all semitic peoples.
Is there such a thing as hostility specifically against all Semitic peoples? Do we need a word for it?
I know people who hate Jews but not all foreigners (foreigner = someone from another ethnicity/race/nationality).
And I know people who hate all foreigners, i.e. xenophobes.
But I have yet to meet someone who specifically hates all Semites.
So do we really need a word to name people that don't exist?
(There are people who hate all Muslims, but they usually do not limit themselves to hating Semitic Muslims.)
otherwise how can one determine exactly which american minority group w.c. fields intended to slur with his observation, "there's an ethiopian in the fuel supply" ?
I figure Fields was just more specific than others.
I guess there are people who hate Ethiopians. But I think they really hate all black people rather than all Semites, Ethiopians being both black and Semitic. (Not that being black has any meaning other than that which people who think it ought to have project onto it.)
Technically, of course, you are right. When hatred for Jews was first called "anti-Semitism", I guess people thought that hatred for Jews is pretty much the same as hatred for all Semites. Now we know this absolutely isn't true:

The problem here, for linguists, is that fanatics rarely care about real taxonomy as much as they care about their own wild fantasies. So while Arabs and Jews are racially of the same stock, the Nazis certainly saw a huge difference between them. And while Gypsies are as Aryan as anyone, the Nazis certainly didn't include them as a nation among the master race.
The Japanese were a leader race, although hardly even related to Aryans. And the most Aryan country of all, Iran, was, after 1942, totally opposed to Nazi Germany. Another oddity was German support for (mostly Semitic) Iraq against (mostly Aryan) Iran.
And while the Nazis claimed that a light skin, non-black hair, and blue eyes were signs of racial superiority they didn't think that Jews (who like some Lebanese and most Imazighen) have lighter skin (and more often blue eyes) than Arabs were the local master race for the Middle-East and North-Africa.
This reminds me of a statement made by my favourite author, Ephraim Kishon about Sabras (native-vorn Jewish Israelis). He said that immigrants from Europe, Ashkenazi Jews, small and weak, were surprised to see that their Israel-born offspring so often turned out to be "strong, blond or red-haired, blue-eyes, exactly like the Nazis described the master race, except a bit taller".