Making a movie adaption of an epic poem is about as sensible as making a film adaption of a manga, anime or comic book. It can be done, but it's risky and you kind of have to know what you're doing.

And yes, there's obviously that whole case of the writers completely cut away the Greek Gods and removed their activity from the narrative entirely. During antiquity the human psyche was more plugged into the Astral Plane that most humans in first world countries are today: so the idea that individuals living in these technologically primitive societies might be able to experience and witness these Tulpas isn't as strange as you might think.

But it sucked b/c most anime film adaptions kind of suck. Super Hero films suck a lot less than anime films, but that's b/c the comic books and the film makers are from the exact same culture, so it's way less challenging and prone to much less misinformation and cultural misunderstanding.