the author nailed it here, "I noticed that I was actually getting a hell of a lot done in not much time at all."
There's no content to it. He doesn't list the pros and cons, he doesn't really detail his thought process he basically just says "I chose Rails so it Won". It's basically a propaganda piece.
I don't fault the author. As a general "this is what's going on with me" post to an established audience it's fine. But I can't see why it's getting voted up on HN
Notice how a comment further up that does nothing but call Rails developers "douchebags" has a high vote count, while other posts that proselytize Rails fare similarly.
There are two camps that are happy to vote en masse for comments that validate their worldview.