A commentator on Reddit has a good idea why movie posters just ain’t what they used to be:
As a person who works in the field of design, occasionally for film promotion, and who laments the current state of film poster art, this is my take on your question:
It is much easier for those who direct a film’s marketing campaign to micromanage and control a Photoshop artist who is simply manipulating photos (basically just moving actors’ heads around) than it is to control an illustrator who creates an actual painting with real paint. If the art director gets the poster art and wants to see one actor’s head 10% bigger, or one actor replaced with another that change is at least a day’s work for a traditional artist. A digital artist can simply swap out one head for another in a matter of seconds, and give you dozens of variations of it in one day. The film promotion art directors and the marketing people they answer to are addicted to that flexibility and the direct control digital photo-based art gives them, and no way are they going back to trusting an artist to paint the picture for them.
Drew Struzan, the guy who painted the BTTF poster above talks about the reasons he left the industry in his book. By the time he retired, the film industry had long switched to digital photobashed art, but Drew was still called upon for special projects, like anything Lucasfilm, or genre films targeting a fanbase that would especially appreciate his talents. It was two last big jobs which seemed to suck the life out of him so much that he’s declared he’s pretty much done making posters. Indiana Jones and the Crystal Skull and one of the Hellboy movies. The marketing people for these multi-million dollar campaigns were no longer simply letting him do his thing. They expected the kind of control over the posters as they get when working with digital photo artists, which is incompatible with Drew’s painting style. Like, they wanted hundreds of compositions sketches for Indiana Jones, which given the schedule is only possible with digital tools. So Drew (who didn’t know how to use Photoshop) had to resort to teaming up with a Photoshop operator and work in tandem with him in a grueling process making hundreds of preliminary compositions, changing every damn little thing they wanted over and over again. A back and forth that could go on forever do to the flexibility of digital art, but something that is not possible with traditional paint. This drove him crazy, and he’s got piles of money now, so he’s basically retired for real now, like for real real real this time, for real (except for that promo poster he did recently for Star Wars Episode VII, although looking at the poster I get the feeling that it was like pulling teeth for him – not fun anymore).
Here’s the discussion on Reddit.