Certainly in films the main character could usually be considered a Mary Sue to some extent. It's subjective whether a particular person considers any character to be a Mary Sue. I suppose most people have varying tolerances to Mary Sue-ish behavior and characterization. If they have other reasons to dislike the character, such as not liking some other aspect of the film or having political/religious/ideological reasons to disagree with, then it doubles as a convenient way of dismissing the character.
So sometimes it's used to discredit a character for another reason, and sometimes someone really just feels that the character is too powerful and it negatively impacts the film. Because someone's enjoyment of a film is largely subjective you shouldn't just assume that it's the former.
So sometimes it's used to discredit a character for another reason, and sometimes someone really just feels that the character is too powerful and it negatively impacts the film. Because someone's enjoyment of a film is largely subjective you shouldn't just assume that it's the former.