That’s been some folks opinion since film’s release, others do not agree. I think it’s more the well documented circumstances that lead to Coppola’s own decent into a little madness during production and there were just far too many loose ends in what was shot to make the narrative as compelling as it was the first two thirds or so (Francis was never the same director after this for sure).

Prior to Brando screwing the pooch, he did a great job with the madness/fog of war feel.

Imperfect as the ending is, It’s still one of the best movies ever made. I think we can all agree on that.

Best to you.