I don’t buy the premise...
but it is pretty dumb to day, ‘kids want to read about people that look like them’, and then tell authors to write more books about minorities. If that was true, why would authors want to limit their audience? Clearly the way to sell more books would be to wrote majority protagonists.
Not that I buy the premise anyway. Leftists have been screaming for more diversity in fiction for years but what they mean by ‘diversity’ is narrowly defined categories of pigment and gender. They don’t want any diversity of ideas.
That was part of the appeal of Twilight, and by extension, 50 shades of Grey. The main female character is totally generic. Average height, brown hair, divorced parents and totally devoid of any personality.
The author did that purposefully, to make it easier for the readers to use her as a self-insert.