I think we need to differentiate between technical questions and political questions. I agree: technical questions are usually best left to the experts. But political questions - questions concerning how society should change and progress - need to be answered democratically by the workers themselves, not by technocrats. Of course, technical and scientific knowledge should inform political decisions; but, ultimately, development should be under democratic control.
For example, the building of a new airport is best overseen by people who have expert knowledge of how an airport is built. But whether that airport should be built in the first place is a social question which needs to be decided upon through a democratic process, by the workers themselves.