It definitely isn't. Tons of people think Arabs are actually native to Egypt, Syria, Iraq, Palestine, etc... or that Turks are native to Turkey/Anatolia. Most Americans and Western Europeans have no clue about the history of Christianity in the Middle East and Turkey, Arab conquests, etc... Or the fact that Christians were still a majority in a Middle Eastern country within the last 100 years.
History is full of migration, conquest, and everything in-between. I always find it a bit odd when people go on about "the Islamic conquest" when your own "native" culture's history is probably not that dissimilar in broad lines.
> Arabs are first mentioned in Biblical and Assyrian texts of the ninth to fifth centuries BC where they appear as inhabiting part of Syria. Proto-Arabs are presumed to have originated from what is now modern-day northern Arabia, Jordan and southern Syria. Over time, Arabs spread further out sometimes replacing previously spoken Semitic languages.
It's not that it's politically incorrect. "Most" people just don't care, except of course when they can use it to get internet points.
The fact that Arabs occupy their current geographic distribution through conquest and migration is not some hidden knowledge or politically incorrect fact. Anyone who has access to wiki can know about it. I've never met anyone who wanted to die upon that hill.
Of course people came from all over the place, by your logic the Japanese are Chinese, the Koreans are Chinese, Indians are central Asian, Greeks and Romans are Arabs, Native Americans are Polynesian and Latin Americans are Spanish.
Or from a higher level just for rhetorics sake, everyone is African.