Why do arabs, specifically egyptian people hate egyptian mau cats? (and short haired cats generally)?

probably because the egyptian mau is a common sight in that area and the egyptian mau was originally domesticated from wild cats in the area. Whereas persians in that area are much more rare and have been domesticated from "pure" bloodlines. Thats really all they care about is bloodlines in any of their animals. Kinda like how heelers are sold for dirt cheap in texas because they are everywhere but they sell for as much as $500 in the northern areas of the U.S. where they are much more rare.