I hope that would help people to discover ML and it will attract more people to it. That is the kind of fun article I missed when I started to wonder what is ML.
Some of the response here I think would be avoided if you added a bit of an introduction to your girlfriend (this doesn't need to be identifying), as it seems to be being taken as a general "women don't know X" rather than "my girlfriend didn't know about X so this is how I explained it". This would also help set the scene a bit, who is the audience? Are they very, slightly, just somewhat or not at all technical?
Perhaps some additions that would be good are what are her questions? What's she asking you in response to these things? They have a good chance of being the kind of questions your readers might be asking too, and so having questions and your answers might be a nice thing to see.
I think it was uncharitable for you to assume he was implying anything about girls generally. If it had been "Machine Learning: for your girlfriend," that could have been reasonable to make that assumption over.
Edit: revising, shortening, done~
There's nothing inclusive in your attitude, only anger and blindness to the most obvious, harmless interpretation.
The author decided not to tell us anything about who he taught -- where on that range she fell -- just what her social role was... His.
That's what people are objecting to: in an article about teaching your gf something, why not make it about who she is as a student and what she learned instead of her social status as your mate?
It's that fundamental phrasing and framing of her, as it being more important to know her social status than anything about her academics, that people object to.
(All that aside, this is a silly thing to complain about. But it isn't nothing.)
Edit: I have to redact a little bit, clearly "my girlfried" is possessive and exclusive, I feel slightly offended. I hope this sounds like sarcasm, although it is petty.
Maybe you should stop shoving politics (no matter how well intentioned) into everything.