The Coens are experts in their ability to write a political satire, or a movie with a strong political message, and make it feel natural and organic to the plot so much so that, even if you don't agree with whatever they are trying to say, you don't care because they are still telling a great story...and the story always comes first.
However, put George Clooney at the helm and all the talent that the Coens have for expertly into a stylish story goes straight out the window.
And the result is...a bore.
Clooney put the politics above the story and you can tell. It felt preachy, it felt pretentious, it felt like a lecture...What it didn't feel like was entertainment.
But that's what happens when you have a great script with a strong political message...and you decide that the political message has to be front and center, in your face, at the expense of actually telling a story.
Had the Coen's actually directed it, they could have sold the audience the same message, without making it feel like it was forced down your throat.