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?

I regard HN community higher for better signal to noise ratio.

I asked this question only because I got curious - I had submitted two links and one of them got highly discussed while the other didn't. Hence.

These days most experts are overloaded with info. Unless someone is constantly pinging them about an issue they aren't going to think about it.

Agreed.