The 'Red River' syndrome ...
Both "The Caine Mutiny" and "Red River" suffer from the same syndrome, both are men's movies with rich and multi-layered interactions, yet for some reason, the writers felt the need to inject some random/artifical romantic subplot while it had nothing to do with the main story.
I understand that "The Caine Mutiny" is an adaptation and the romance played a significant part of the novel's plot, I understand it's supposed to highlight Keith's maturation BUT that's why we say 'adapted screenplay' and that's why "The Godfather" was a masterpiece, had it kept all the novel's sleazy details, I doubt the film would have been so highly regarded, this is why "One Flew Over the Cuckoo's Nest" is a masterpiece, it chose to focus on McMurphy instead of telling the story from the Chief's perspective.
Keith might have been the central character of the film, but the story inside the Caine was so thrilling that anything happening outside would have distracted from the film's entertaining value. I can't believe such a wonderful screeplay with so many three-dimensional and ambiguous characters could indulge to such artificial clichés. How can a film so great have so many weak parts? Especially since 'Keith' isn't quite the flamboyant character, not with a cast that includes Humphrey Bogart, Jose Ferrer or Fred McMurray.
Robert Francis is not to blame though, his performance is quite all right given the kind of character he plays, he's supposed to be the passive observer, the obedient ensign whom we can identify with. Keith embodied our viewer's position, he was like the journalist in "Das Boot", a neutral character whose judgment can only be based on what happens during the film (since it was his first mission) and then we're tempted to feel and think his way.
So, I agree with those who can't stand the romantic subplot, but I don't hate it because it's bad, but just because without it, "The Caine Mutiny" would've been one hell of a masterpiece, now, I think it's one of the greatest dramas of the 50's, but only because the little twist at the end, and the extraordinary performances of Bogart and Ferrer redeem these flaws.
"Darth Vader is scary and I The Godfather"