The problem with the perception of film producers and their role in film producing companies is that they vary quite a lot in what individuals actually bring to the table.
The best film producers I have ever met are in fact the great motivators. Sure, some people think that the producers are just the people with cash but that is just not true.
I have met many great producers that did not become film producers simply by having money to throw at a project. The great film producers are the individuals that can kick a door down that stands in the way of finishing a project.