On a side note, "Mickey Mouse Management" usually refers to Walt Disney's management style, which is mostly considered an example of creative and successful leadership. So I don't think Scott Adams really had Mickey Mouse in mind here.
I like the clown theory best. Maybe the nose was supposed to be red (remember Scott Adams does not color the strips himself). However, the coloring goons are probably only supposed to add non-black colors, so that makes this theory less credible.