I disagree - I think for the most part there is a wisdom of the masses where sure not EVERY SINGLE person will have the same image of a character but if you had a character artist draw out what 1000 people think of that character you'd find they converge pretty closely... the problem happens when the casting is not close to that convergence and is far out on the fringes.
As I said before I think if you are looking to make a product based on an existing IP you are doing so because you want that built-in audience that IP has - if you can't make the effort to ensure you are honoring how that audience expectations then your project deserves to fail.
The place to do experiments with gender-bending, race swapping, expectation subversion etc is in original IP's that hommage the older franchises.