It's a funny thing about movie making partnerships isn't it? Remove one half of the partnership and somehow for whatever reason the other half of the partnership doesn't do as well.
Contrary to popular belief, it was not George Lucas and George Lucas alone that made "Star Wars" (1977) and "Empire Strikes Back" (1980) such great movies. It was also his producing partner Gary Kurtz who contributed his fair share of great ideas for both films. A funny thing happened when "Return of the Jedi" (1983) began production. Gary Kurtz left George Lucas to himself to make that movie, as Kurtz was not happy with the direction Lucas was going with the script: Gary Kurtz left the production and instead went on to produce "The Dark Crystal" for Jim Henson. Gary Kurtz did not agree with the following bad ideas of George Lucas:
1. Rehashing the "Death Star"
2. Making Luke and Leia brother and sister (after the previous two films when both of them were potential lovers)
3. The Ewoks
4. The happy ending
5. Keep Han Solo alive instead of killing him off
Lucas of course made all of these bad decisions by himself in order to boost toy sales for "Star Wars" merchandise. Needless to say, "Return of The Jedi" was a bad movie because Gary Kurtz was not involved in making it, and did not have equal imput into pitching ideas, leading to his departure. It is my opinion that "Return of The Jedi" was the beginning of the end of the "Star Wars" saga due solely to the absence of Gary Kurtz.
The highly regarded (by some) "X-Men" and "X-Men 2" movies most definitely benefited from Tom DeSanto being there on equal footing with Bryan Singer. Take Tom DeSanto out of the equation (like Gary Kurtz) and leave Bryan Singer to himself (like George Lucas) and no one is there to keep Bryan Singer's eccentric ideas in check (like George Lucas), such as in "Superman Returns"...
1. "Superman" hardly having any dialogue
2. "Lois Lane" looking like she was barely out of her teens
3. Every other cast member looking like they phoned in their performances while on "downers."
4. Lex Luthor played like a psychopath.
5. The little kid obviously in need of psychiatric help, despite the fact that he was supposed to be half Kryptonian.
6. "Superman" getting stabbed
7. Minimal dialogue for Brandon Routh to perhaps hide the fact that he really couldn't act very well?
"Superman Returns" most definitely would have been a 1000% better movie if Tom DeSanto were still partnered with Bryan Singer at the time. It's a tragedy that the partnership had disolved by that time.