Good communication is core to trying to accomplish anything complex, which is why I'm blown away by people who are able to get huge projects like feature films made, which require so many exacting details managed by a massive number of people to not mess up. It helps to some degree that there is some limitation on what is possible, and far more on what's expected, making it a lot easier to imagine how it should be accomplished. There is similar comfort in something like playing an instrument--while you can experiment with how it sounds massively, at least you don't have to worry about sounds it can't make.
But the more blank canvas there is for each person involved in a project, the harder it's going to be for imaginations to get boiled down to something communicable. If I approach someone saying “I want to make an art piece with you which communicates sadness,” there are about a million ways either of us could approach that, and we will likely have to narrow down many specifics such as what medium we are working with, whether we have similar conceptions of the theme, and whether we are even capable of representing that theme effectively together.
One of the toughest things about my career has always been a relative lack of precedent for what I am trying to do, and my inability to communicate it to others. Usually I gravitate towards working with people who are similar enough in tastes, worldview, and skillset that I am confident they can fulfill my intentions with minimal instruction--or even who I am comfortable allowing to fundamentally reshape the character of the work out of trust for their ability to make it better than I could have.
In that respect, I am more of a 'band member' than a 'singer-songwriter,’ at least when it comes to working with others. In fact, I honestly have very little interest in giving people specific instructions on how to do things, because I am so much more likely to be interested in working with someone in the first place if I think I could set a framework for them to create something interesting out of their own creativity.
This is pretty limiting, though, in that it only allows me to realize ideas which either can be accomplished almost independently, or which leave a lot of room for others to do their own thing. Granted, I have to imagine that even directors feel more like band leaders than absolute authorities on how their film comes out, since they still have to work with the abilities the people around them have—and if those people are really good then the director should probably be listening to their ideas as well.
There's also a level where you can be so good that no one would instruct you on your part. The best reason in my mind to always be writing is it's the one thing I never get questioned about at all. It has become a place of great power and security for me to know that no matter how poorly I may communicate otherwise or how much trouble I can have working with others, at least I can write my ass off--and I want to be good enough to be hirable on the basis you just wouldn't want to dilute my unique mark on your project.
The problém the director has is that even if je works more as a band member, as you say, he is still burdened with the perception of responsibility.
Uncreative people need a responsible guy, because they can't imagine all the contributions of the people in the credits. Without that, the credit falls to the studio. Which creates a lot of problems nowadays.