Orientalism is something that is rarely discussed outside of academia and yet is pervasive in Western society. Though most parents don't typically outright say to their children things like "Asian cultures, specifically West Asian cultures, are strange, mystical, and exotic, and you should not trust Middle Eastern men because they are scheming and unintelligent," people are still exposed to this mindset from a very young age. The source of that exposure is, of course, the media.
One of the most infamous examples of Orientalism in modern-day culture is the movie Aladdin. This movie is a favorite among younger children, but is an obvious example of the stereotypes surrounding the Middle East in movies. There are many more examples of movies about the Middle East or East Asia which clearly portray harmful stereotypes about them, but possibly the main source behind the pervasiveness of Orientalism is more subtle. Think of practically any sci-fi movie. There are likely several fictional cultures in this movie, and it is also likely that one or more of them are logical, behave in familiar or relatable ways, and look just like the generic idea of a Star Trek-esque future. But there is also likely another culture. This one is mystical, easily overpowered, lacking in technological advancements, and, most importantly, exotic. Their clothes, fashion, and even speech do not look or sound generic or even familiar, and the parts featuring this group of people are often the most beautiful parts of the movie. However, this imaginary culture is not actually original or even made up: it is almost always simply based on ideas of Asia.
Though there is nothing wrong with respectfully taking artistic inspiration from other cultures, it is pretty self-explanatory why portraying vaguely Asian cultures almost exclusively as literal aliens is problematic. The problem is, the creators of these movies likely don't know what they're doing: they actually believe, subconsciously or not, that Asian cultures are mystical, incomprehensible, and alien. And by seeing aspects of those cultures portrayed as such over and over, the general public begins to have the same idea ingrained in their minds, reinforcing Orientalism once again.