Earlier quoted context omitted.
> This has become problematic when we use the plural. Grammatically, it's not problematic at all. Some people with new ideas completely out of line with the culture at large make a big deal of it.
“Completely out of line with the culture” firefighter, for a moment, was an exclusively male job. Fireman made sense. As more women took on that job during the past 50-ish years, calling them “firemen” makes less and less sense. So to say it’s people out of step with culture isn’t quite right. It’s more like entrenched language in conflict with shifting culture. A non-gendered example of this would be something like…
Historically, the masculine noun class has been used in gender-indeterminate places, but about 100 years ago that usage stared to disappear from the language, or at least become argot. The phrase "I am no man" in the Lord or the Rings is a play on this disappearance.
In English, this disappearance happened alongside a similar change in gender roles; however, in a lot of European languages the social changes occurred, but the linguistic changes did not (and non-European languages often have quite different kinds of noun classes).