Reddit has the same phenomenon where the audience doing the upvotes is very different to the audience posting comments. As I'm in the second group I would love to say it's because people who read comments are smarter than those who just look at the main content. Smarter or not it's a different userbase and it creates some conflict.

Seems like the divide between the voters who vote in the Primaries and the voters who vote in the actual Election. Vocal minority vs. Silent majority.

Goomba fallacy

Different posts on HN can attract different audiences.

I can't say I've seen the same universally, but, if it is s trend, it would seem one invites discussion between humans on the site while the other seeks to minimize it.

It's because it's a novel solution to "I lost my phone".

Most of the responses here are negative. Seems consistent.