Wow!
Personally Goki, if the supposed 'think-tanks' at these particular studios weren't lining up to a homeless shelter after the release of Episode IV, then they should've been!

IMO United Artists didn't want to pick it up because they were already working on Logan's Run and probably couldn't afford to pick Star Wars up even if they wanted to especially since they followed that up with the original Carrie.

Universal Studios... I don't know why they didn't pick it up if they liked it so much? I mean, considering the garbage they were putting out at the time, the only truly decent, but hell awesome!, movie they put out between 74 and 76 was Jaws - so I guess they wanted to pursue a quote 'more wholesome' brand of entertainment at the time.

This sort of reminds me of the story John Cleese divulged on the Graham Norton Show with regards to the original pitch (1:14) for Faulty Towers.