Definitely a factor. But also technology. We’ve only been able to make convincing CGI of alien creatures for the past 20 years or so. Before that it was always a person in a suit or with some plastic stuff stuck on their faces.

On top of that, most movies and TV shows are made to appeal to as wide an audience as possible. That’s why the characters have to be relatable. Therefore every creature somehow has a humanoid face with humanoid facial expressions.