Even if you only want to write science fiction, you should also read mysteries, poetry, mainstream literature, history, biography, philosophy, and science.
I can't speak for the other authors, but what I hoped to achieve was to illuminate certain corners of the Lucas universe that hadn't yet been explored.
I found college useful for a lot of other reasons. It exposed me to a great many influences I wouldn't otherwise have encountered, and gave me a lot of time with some very intelligent people whose thoughts are still with me.
I've learned that I get blocked when my subconscious mind is telling me that I've taken the work in a wrong direction, and that once I start listening to what my subconscious is trying to tell me, I can work out the problem and get moving again.