I wish the author at least postulated some reasons why Rails became popular:
* It launched before the other web frameworks of its nature (in fact, many were inspired by it).
* It hit API stability many years before Django did.
* It's a lot more flexible than most PHP frameworks.
* Ruby makes pretty, domain-specific languages easy.
* Rails, while allowing you to override defaults, doesn't ask you if you don't care.
* The features have kept coming in Rails with regular releases increasing its value. Many of the additions have come from real-world, high-value projects. That can't be said for many frameworks which were built as "we can make Rails in (Java|PHP|Python|etc.)".
Rails has hit a tipping point, but the interesting question is why. The author hasn't put anything forward there. In fact, the author has some downright weird statements. He can't find anything bad to say about Django? Rails just plain sucks? Yet Rails wins? Even some of the things he mentions - such as coupling data objects to the database - are done in Django (and most of these style frameworks) in a similar fashion. So, that sucks in Rails and doesn't in Django. Hmm.
It's a great attempt to create one of those articles people love to read that say, "this sucks, but it's still what you should be doing because it doesn't matter that it sucks".