Is Lawrence Kasdan contribution to Episode 5 (& 6) overrated ?

No.

 

I think George's decision to not replace Leigh Brackett's name (apart from what we know from the existing official explanation) just shows what a lack of ego the man has. Yet another reason to admire him

I'm not sure about how much credit can be placed at the feet of any one person when it comes to co-writing. For example, Kasdan gets all the credit but it was Harrison Ford who came up with the line "I know". And how much of what George gets criticised for in the screenplay for Attack of The Clones is actually the work of Jonathan Hales?

That's the problem (well, one of them) with the loud-mouthed dectractors, they are very partial with their criticisms of the films. Anything they like is all down to the work of everyone but George Lucas. And everything they don't like, must surely be George's fault. I'm reminded of a time around the late nineties (before the prequels but after the special editions) when a friend of mine who is also a 1st generation fan compared the writing credits of TESB to ROTJ - Kasdan and Brackett vs Kasdan and Lucas - and rather sniffily said "Well, that figures". I pinpoint that moment as when the rot set in and the fans whose childhoods had been so enriched by George Lucas started to turn on him. Since then the relationship between those fans (that happy breed of moaners and whingers) has been akin to that of the violent and irrational man who suddenly decides to start battering his wife - George has really done nothing to earn such treatment, but he gets it anyway. No wonder he sold the company.

What was the question again?! Oh, yes, is Lawrence Kasdan's contribution overrated? No, I don't think so. I look at the films in which he had a hand in writing and I listen to his comments on commentaries and watch him in documentaries and I think he's a sound bloke with a great talent. But should he receive sole credit for the greatness of those screenplays? No, of course not.

 

He contributed that's all that matters, fans know it, that's enough.

 

I don't think so. He was pretty valuable. But George came up with the most brilliant part. Revealing Vader was Luke's father.

 

Kasdan did a great job, imo.

 

TBPH I didn't have a real opinion on the subject until a few days ago, when I learned about Kasdan's mindset for the outcome of ROJ:

"Another dark idea that Lawrence Kasdan had for the ending was to have Luke put on Vader's mask and say that he's now going to destroy the Rebel fleet and rule the universe. It was discussed that in his confrontation with the Emperor, Luke could pretend that he'd been turned to the Dark side. The Emperor would then take him to the controls and tell him to destroy the Rebel fleet; instead, Luke would aim at the Emperor's home planet of Had Abbadon and destroy it." - Annotated Screenplays

Kasdan: Which we are never going to do […] I am telling you that the key is to stick Luke into the center of this in an effective way, so that in fulfilling his destiny he helps the rebellion to defeat the Empire. That is what we are not doing. There has to be some transfer of power from the Emperor to Luke. That would be very poetic in terms of your whole story. That would be the perfect thing if you had a moment when all these Imperial guys see Luke take over. That would be a real Olympian conclusion to this trilogy.

Lucas: Explain that further.

Kasdan: Luke usurps all the power of the Emperor in their final confrontation and is recognized as the ultimate power in the galaxy.

Lucas: Luke can’t rule the universe, because if he’s destroyed the Emperor and, consequently, the Empire, then it’s a Republic again and the senate will come back. They will elect their own officials. He is a warrior. He is a Jedi Knight. He does not want to be mayor, he does not want to be president; he has sworn to be a police officer and that’s what he wants to do.

While I wouldn't know whether Kasdan's contributions are objectively over- or underrated, I believe the above anecdote cleary tells me that George Lucas' contributions are apparently and way too often underrated.

 

Well, technically, it was Lucas who actually suggested it according to the transcript of the story conference from July, 1981...

Lucas: If the Emperor does pull out a secret weapon and the weapon is working, and they wipe out half the fleet, it becomes even more intense. Then Vader knocks the Emperor into the gun and he is killed by his own gun, and in the process the gun blows up in a big explosion. Luke is all right, Vader is coming apart. I think it's be great for Luke to try to help Vader while the thing is blowing up. And then Vader gets his cape caught in the door and says, "Leave without me" and Luke takes his mask off - and then Luke puts it on and says "Now I am Vader." Surprise! The ultimate twist. "Now I will go and kill the fleet and I will rule the universe."
Kasdan: That's what I think should happen.
Lucas: No, no, no. Come on, this is for kids.

I suppose the point is, everyone at those story conferneces was throwing out all kinds of crazy ideas before they agreed on something satisfactory - that's kind of how they work... some of it was light-hearted, some of it was not - seems to me Lucas, Kasdan and Marquand all had equally valuable input in that process, judging by the ROTJ conference transcript...

Ultimately, I think it is unfair to judge Kasdan (and/or Lucas, Kershner and Marquand by the same token) purely on the basis of how the finished film reflects things "they suggested".
It's a collaborative process, and it is clearly just as valuable, for example, for Kasdan to challenge Lucas to address problems with his screenplay by pointing out the issues or suggesting alternatives, even if those alternatives didn't necessarily always become the eventual solution.

 

It's as overrated as his contribution to "The Force Awakens", which as far as I'm concerned, was a piece of crap.

 

Interesting, but still. I think it's pretty obvious that Lucas did this in jest, but it's Kasdan's earnestness hat somehow sticks out like the proverbial sore thumb.

Can't help to imagine the scene with Gary Kurtz in the place of Kasdan:

Kurtz: (says no word, his face is petrified in sheer horror at the suggestion)
Lucas: Come on Gary, you know I was just kidding, right? RIGHT?