Lily Rose Depp in Nosferatu was terrible. Her bogged face kept taking me out of the movie.
The lack of make-up did her no favours. But her casting was only one of a list of problems with that movie. Lovely sets, lovely costumes, some nice though over-stylised composition. But everything else about the movie was bad.
There can totally be bad casting in a bad movie, but for me it only really stands out when you have bad casting in an otherwise good movie.
I feel there's a third category too though - bad casting where it's not so much it makes the movie bad but into something very different to what it might have been. Arnold Schwarzenegger as the Terminator. Iconic, right? Nobody ever imagines anything other than him, right? For the most part that's true but Arnold always has some level of cheese that you never escape. Look at Robert Patrick in the sequel or Cromartie in The Sarah Connor Chronicles TV show. I know they're both later models canonically that are supposed to be more able to interact with humans but that's an in-universe explanation for frankly better casting.
Cromartie stalking and then running after John is much more actually scary than Arnie wading through a hail of bullets because he's so cool.
Or Shirley Manson, even though her background is as a singer, does a very good job as a terminator replacing an existing real woman (who has a young daughter). You can see her learning and improving throughout the series. Especially creepy is near the end of the episode you see her repeat Ellison's comments about his father's passing almost word for word to her "daughter", simply copying and re-purposing his dialogue to seem more authentic.
I think Arnie is bad casting as the iconic terminator not because he was bad in the role exactly - the franchise was a huge success. But because his Arnie-ness took away from what I think could have been a much better version. Something with a bit more real edge.