Mozart... wrote the same thing over and over again.
I agree with your larger point but vehemently disagree with this example. I'd elaborate but I'm getting tired just thinking about it.
I will say that even Wes Anderson's bad films are beautifully shot, edited, and scored.
Also that there's nothing wrong with being a one-note if it's a good one.
That said, Owen Wilson and Jason Schwartzman need to call it a day.