That's what I thought as well. If someone's opening metaclasses to define singleton methods they probably know all about the Ruby object model. I don't see how it could be done "without knowing you're doing so".

The people who did it first did understand the meta model.

Unfortunately some people started following without full understanding. I wasn't at forefront of things back then, so I only noticed when the people who did know better started to writing about abuse of this technique.