I'd like to refer to a hypothetical person in my documentation
Try something like this:
When a user visits the website, they will be assigned a session ID, and it will be transmitted to them in the HTTP response and stored in their browser.
But not like this!
When a user visits the website, he will be assigned a session ID, and it will be transmitted to him in the HTTP response and stored in his browser.
Using gendered pronouns signals to the audience your assumptions about who they are, and very often lets them know that they don't belong. Since that's not your intent, better to just be gender neutral.
And if you don't believe me, some folks did some science (other studies have consistently reproduced this result).
Can I just go 50/50 on male and female pronouns?
It's a nice idea, unfortunately it doesn't work. Your users don't read your documentation cover to cover, so they won't be able to see your good intentions. Instead they'll be linked somewhere in the middle, see your gendered language, and feel excluded.
In addition, not everyone identifies by male or female pronouns. Play it safe, just be gender neutral.
Using the plural pronouns isn't grammatically correct!
I've been assured by people far more knowlegable than I that it's ok, even Shakespeare did it. Personally, I'm comforted by the knowledge that even if I'm wrong about the grammar, I won't have made anyone feel excluded.
Someone sent a pull request to my project changing the languages!
So merge it! If you've got some process that a contributors needs to go through (such as a CLA), let them know. They're just trying to make your community better and bigger!
They said I was being hostile!
I'm sorry, but you were. Your choice of language has an impact on people.
I wasn't trying to be!
That's ok, hostility isn't about intent, your words had an impact whether you meant it or not.
Maybe you didn't know, you're not a native English speaker, your 11th grade English teacher beat you over the head with some bad advice. That's ok, it only takes a moment to fix it, and then you're letting everyone know it's easy to fix!
Aren't there bigger issues we should be dealing with?
There are so many giant issues we face. This one takes 15 seconds to fix, has no downsides, and we can all be a part of making it better. If we can't do this, how could we ever tackle the other challenges?
Has anyone ever asked these questions?
You have no idea.
Some of these aren't questions!