It's always hard to understand exactly why any given submission does or doesn't "catch". It could be as simple as bad timing - another very popular story had everyone's attention captured when it was posted, or maybe there had been a recent rash of similar articles and people were burned out on the topic, etc., etc. Or maybe the headline wasn't click-baity enough, who's to say?

All of that said, why would you think HN is "the best" place to talk about that topic? ML is certainly a frequent topic of conversation here, but HN isn't - strictly speaking - a "machine learning community". Maybe Reddit's /r/machinelearning or another community would be better?