English speakers used to distinguish between thou, a word used to address a single person, and you, a word used to address more than one person. Just as kings used a royal, plural we when referring to one person, English speakers came to use a flattering you when addressing a single person. The Quakers retained thou to avoid elevating anyone with you. To non-Quakers, this standing on principle sounded antiquated and pedantic.
Today we face a similar problem that mixes plurality and sociology: we are told that the singular, third person pronoun is he. We are told that she implies a gender; while to say he could mean either male or genderless. This is confusing, so in speech we use a singular they. (“Some_one_ came up to me and they said…”) We are told that, in writing, it is incorrect to use the singular they because they “should be” plural. Instead we are told to use he, which “should be” (or, preposterously, “is”) genderless.
He and she are gendered now and have always been gendered. When he was first used, it was believed that men were genderless: men were people and women—the she—were something different. The he-is-genderless rule was not a product of rational grammatical thought; it was the result of a long history of misogyny. Today I hear some wishy-washy in-between to justify this rule: women are people, but we only have he and she to pick from, and he has historically been used to refer a person, so let us stick with he. This is a mistake.
I say, let us call a single person they, keeping he for men and she for women. Let us do in our writing as we do in our speech. Maybe this is bad for grammar, but it is good for women, and I would rather grammar suffer than women.