Yet, it certainly is important to make the proper choices when picking up style. Similarly to fashion, code style reflects our credo as developers, our values and philosophy. In order to make an informed decision, it’s mandatory to understand the issue at stake well. We all have defined class methods many times, but do we really know how do they work?

I don't think seeing it in Rails PRs naturally means we should do it blankly. Put it another way, what's the justification in those PRs for doing it?

If you don't understand both sides of an issue, you cannot make an intelligent choice; in fact, if you don't understand all the ramifications of your actions, you're not designing at all. You're stumbling in the dark.