It's been a very, very long time since I watched any DS9. This has nothing to do with Sisco's actual abilities but how Star Fleet looked at him. Correct me if I'm wrong but wasn't Sisko considered a burn out and that's why he got the DS9 assignment? It was a little back water of no real importance. Then the worm hole is discovered and DS9 is a big deal. If Star Fleet considered Sisko a burn out why didn't they reassign him to something else and put a more competent commander in his place?