Originally Posted by LegendAssemble
Thats because he was supposed to die, twice. First they weren't sure if Han would return for Jedi (haha pun) and they planned for him to die in the carbon freeze and replace him with Lando. Then after Harrison agreed they decided he survives, but was scheduled to die in the next film because has Kurtz and Ford felt "he had nowhere left to go". However Lucas had a change of heart even making the slightly humorous statement "I don't think I can sell too many dead Han toys". So his death was written out of Jedi. Lando was supposed to take his role for that movie (The reason he's flying the Falcon into battle and not Han in the first place).
The biggest flaw of Return of the Jedi IMO is that it has the production values of a made for TV movie. Lucas's personal life had been ruined and he was left with his kids he just wanted to be done with Star Wars and as a result it doesn't have that passion the first two did. Perhaps this is why the Luke vs Vader scenes had so much more emotion than the rest of the film, perhaps Lucas too realized he was becoming his father as well.
Rewatching 'Jedi' again and it's not so much the dialog that's the problem though I feel this time around Lucas has more say in the actual script than in 'Empire'; it doesn't have the consistency of 'Empire' but there are moments of great dialog here..probably from Kasdan. Ignoring the Ewoks, I think it's the structure of the story and the tone that's a bit uneven. I'd agree that the second act is a long stretch until Luke encounters Vader again.
And Ford did an admirable job of giving Han the right amount of energy despite him not wanting to do 'Jedi' in the first place. Unlike Connery whose performances in the later Bond movies were bored and flat. Not a knock against Connery though since he later regain energy as an older man in the 80's, but you're an actor. Act!
But yeah, Han didn't have a whole lot to do besides a few quips here and there, and yeah, it feels like it was a rewrite to fit Han into the plot after Ford agreed/forced to come back.
He wasn't even involved in the Speeder bike scene...All he got from Endor was being humped by an Ewok. Even in the battle of Endor, he didn't do a whole lot besides hotwiring the bases' door.