Fair enough, although Lucas is credited with the story (not necessarily the screenplay). I suspect this is the way of representing the influence and final say he had over most aspects of the story.
Lots of people like V, and think its the best of the series. I'm not saying I didn't like it, but there are parts of the story and dialogue that are irritatingly simple and shallow, which I guess is my way of saying childish. Every interaction that Luke has with Yoda makes me cringe. V was the movie where R2D2, C3PO, and Chewie began the transition from real characters into toys. Personally, I never liked the way they handled the Lando character (way too shallow), or they way they handled dead Obi Wan (just let the character die gracefully, please). To me, all of those facets of the story were like they were written by an adolescent.
That's just my opinion, though, and I recognize that there are good parts to V, and that many people liked it a lot. Hell, I liked it. It's probably a bit much for me to characterize it as "childish," I'll admit, like VI certainly is. Maybe better to say its "adolescent."