Hollywood's sequel fetish has been around a long time and unifying IP's are a natural marriage for it. Part of the reason Lucas sold off Lucasfilm to begin with was he couldn't get any of the studios interested in striking a distribution deal (on favorable enough terms anyway) for anything that wasn't Star Wars or Indiana Jones, two properties he was tired of dealing with fan expectations over.
So he was intentionally making them into garbage so they would let him change universes? Explains a lot.