Wanting someone and actually asking them to direct are two different things. With Lucas' tussle with the DGA it wasn't about to happen, unless Speilberg left the guild, which would have likely caused problems down the line for Steven and several other projects.

Between directing Raiders, E.T., and Temple of Doom in that time frame, not to mention being executive producer on Gremlins and Poltergeist, (which some people believe he ghost directed to this day) I don't see how he could have ever slotted Jedi in.