That's your mistake.
They have nothing against your origin, you just don't have a valid passport.
Proof: an Israeli national can fly KU if he/she carries a US passport.
They have nothing against your origin? If that were true, there would be diplomatic relations between Kuwait and Israel, but there isn't, so we know that statement is preposterous.
Fact is, they are discriminating against Israelis through proxy, and there is another case currently before the D.C Court of Appeals that is set to decide the matter.
Saying, "Oh, I don't hate Chassidim, I just don't allow anyone in my restaurant who has side-locks, black hats, and black coats," is in effect doing exactly what you say you're not doing, and which is illegal in this great country.