It's supposedly the assumption that matters. I read it that Kepler was bothered by the rudeness to most people, assuming neutered pronouns for everyone, for the hypothetical sake of the 1%. (Note, the 1% are not here asking for this of course, because they don't want to be associated with these behaviors.)

Rules for thee, and not me. That's bad enough, but when someone is speaking for an entire population and using language like hate and shame they aren't helping anyone.