Is there seriously an argument to be made for a pro-"he" side? I don't understand how people both say "there should be a debate" and also "it's one word in meaningless documentation".
Oh yes there is. He and She can only refer to people while They can refer to things, too. Take for example: "if a person wishes to rungle the querts, they need to configure them such so that they will be in the state indicated by the widget manager". A sentence like that, while ultimately understandable, does cause me mild confusion at first read, and I'm sure I can come up with a more natural-sounding, but more confusing example, if I weren't so tired.
From my point of view, English is basically fucked. You've ended up with third person pronouns that are irredeemably connected with the gender of the person they describe. They is really a cludge that sort of works, but isn't quite a drop-in replacement for good old She and He.
I'd use They when the text can flow naturally with it, but drop to She/He when it starts sounding ambiguous or use any other kind of description. If writing instruction manuals, I'd use You to refer to the user at all times, or just drop to passive form and not mention people's genders at all.
There's probably an argument for it, yes. I can't imagine that it's a very good one, but I imagine that it exists. (There's always an argument for the status quo, which is "this is how we've always done it", and there's certainly a tradition of using "he" as a singular pronoun).
In any case, I am contrasting "debate" with "we would fire you for not agreeing with us". Debate does not imply that both sides are equal, but it does mean that people are given the opportunity to hear both sides of an argument and decide what they want to do. If Ben Noordhuis still thinks that gendered pronouns are a good idea after this debate, he's still entitled to his opinion, but if Joyent are the owners of the project he's working on then he'll have to keep his opinion to himself when working on that project.
"He" (or sometimes alternation between "he" and "she") is stipulated in some older style manuals (I think the New Yorker still uses the latter, say).
There are also some people who seem to be under the impression that singular they is a neologism created by an imagined political correctness conspiracy (of course, they're wrong; it's been in use for over five centuries).
