>My point is that if you pick a diverse audience, you will come up with a diverse set of expectations.

You don't "pick" a diverse audience; you respect the audience/fandom how it currently is. I refuse to believe that if you surveyed ANY fandom and asked them to do a character description of the main character, they wouldn't come to a fairly common consensus overall.

>which is, like, accidentally racism.

No it's not, it's people saying the character isn't as they expected them to be - and again that's on the person using the franchise to match what they are creating to that built-in audience FIRST and FOREMOST - if they don't want to respect that audience they shouldn't be touching the franchise they should be making something original.