I'll use Ian Fleming's *The Spy Who Loved Me* as an example.
Huge backlash.
I personally think that a lot of it rings true, but people to this day freak out. The problem? One female protagonist is suddenly representative of all women.
Is James Bond held to the same standard? Does he represent all men? No. But for some reason, Viv Michel is immediately brunted with the burden of assuming all women are her.
This kind of criticism of fiction is nonsensical; it's the wrong approach to dismantling the whole goddamn thing. To suggest that a man can't author a woman as a protagonist may as well say a man can't author a woman as a character; and where do we stop? Nobody can write anyone who isn't themselves into any work. Are you black? Sorry, you can't have someone in your book who is Hispanic, it might be contrived.
Critiquing literature is natural and fine, but these misconceptions that because "a" character "is" this thing, it somehow must translate into the author's intention that "all" people who "are" that thing are the character... it's frustrating and ridiculous.