English is a fascinating language. People have made up rules about not doing things that basically everyone does. We are told that many things that sound perfectly good don't sound good (split infinitives, sentences ending with prepositions, passive sentences, etc.). I cannot think of a single example of such a bad rule in German.
Take the example of the gender-neutral use of "they." Some 15 years ago, I wrote a long-since-lost article for the University of Freiburg's English department's magazine explaining why this is perfectly good English. Now, I see that a linguistics student in the US has just summed up everything quite well, even pointing out that
There has literally been no point since 1400 when singular they went unattested in contemporary English.
Essentially, the gender-neutral he was insisted on by some zany grammarians, who had obviously learned too much Latin, some 200 years ago. The blogger unfortunately does not mention the evolution of the gender-neutral he (which is too bad, because he provides a number of quite impressive references to support the gender-neutral), nor does he point out that everyone basically exclusively accepts the gender-neutral they in question tags, like the one in the title of this post. No native speaker of English can accept "Everybody thought it was stupid, didn't he?"
You could also point out, as I used to do, that other languages have no problem with pronouns that are both singular and plural. German has sie, and Durch zij, both of which can be used to mean that she is and they are (sie ist / sie sind and zij is / zij zijn). French vous and English you are also used both for the singular and plural, though both never take a singular verb. (French actually doesn't even have a difference between his and her: j'ai trouvé son chapeau could mean I found his or her hat -- you cannot know.) But the other blogger actually tries to argue that the gender-neutral they does not have to be thought of as a pronoun at all, if I understand him correctly -- but read it for yourself.
In trying to raise my children in Germany to speak proper English, I repeatedly have to tell them not to say things like "everybody has to bring his own sports clothes," which I cannot imagine sixth-graders in the US saying. It's not native English. In fact, it's a typical mistake that Germans make; there is no option to the German "jeder muß seine eigenen Sportklamotten mitbringen."
In fact, I remember learning not to say "everyone has to do their own work" in 10th grade, and everyone in the class thought it was stupid... didn't they?