You are no linguist, and I seriously doubt you have consulted a linguist. English teachers are also often linguists.

but words to describe gender have changed many times before

I would love to see an example of this.

It just doesn't work like that. I bet my vocabulary and style are different than yours; but I'm still writing English. And you are. And Tolkien was written in English. And Shakespeare was written and English. We all speak and write differently, often using completely different grammar and spelling; who is "right"?

Not sure what your point is here. All of them are right. All of them used the basic rules of English. There's nothing wrong with speaking and writing differently. I can use different words than you and still use English. Different writers have different tones and subtle patterns in word choice and pacing. That's because everybody is different, and it gives beauty to the language. But without a base to build that off of, you can't have beauty. Instead, you have countless little different languages that make it terribly difficult to communicate. Just a quick question, have you traveled much at all? When you go to different places, they will give you so much hell for not talking like them. Imagine if the very basis for our communication was different. We'd have nothing but confusion.

Also, you are wrong to assume that nobody has any authority in English. I mean you can make whatever sounds out of your mouth that you want to, but if you want to define it as English and be commonly understood and respected, then you're going to need to look to people like Oxford, Harvard, Britannica and the like. Colleges and Universities across the globe look to them. The people there are scholars (yes, Linguists) who have studied English and could probably speak to you in all sorts of dialects you've never heard of. They understand the underlying systems that guide the communication ebb and flo that English provides. Every language is different in how that works. English has it's own unique style of communication, and there is a reason that it is the official language of the U.N. and commonly used in political and business endeavors worldwide. In fact, courts of law also have standards by which they define things; I mean there's a reason law books and court cases have very fancy, specific language. Foreign courts chose English for a number of reasons, including the way things are defined and communicated with it. This stuff doesn't just "happen."