It's about having real-world validation. Anyone can have an opinion about art and literature. If your opinion happens to mirror the opinions of English department academics -- just clever enough to be a new twist, but not so brilliant as to go outside of the culture -- you can get a position as a scholar, and keep writing papers within a mutual appreciation society of academics all thinking roughly the same thoughts. Eventually, the whole crew goes down one rabbithole or other.
A group of thousands of self-supporting, mutually reaffirming "intelligent scholars, designers, artists, philosophers, and religious figures" doesn't make that opinion any more right or valid than my own.
On the other hand, if an engineer can make the fastest sailboat, that's external real-world validation that they got something right.
As a subtle point, I'll trust the opinion of filmmakers who receive public acclaim (external validation). I'll trust the opinion of filmmakers of niche artistic films a lot less. That is to say, I'll trust them about the technical aspects (what aperture means, or how to edit a video), but not about the artistic aspects: how you use film as a medium for communication, expression, and so on. A big part of communication and art is understanding the audience, and they haven't demonstrated they can do that, at least outside of their own clique.