Is there a problem? If they don't know, there's not much harm. But surely this is part of the learning process. Understanding leads to enlightenment. There's certainly evidence that tons of developers using JavaScript don't know how classes work.

I can call methods on objects in most frameworks/libraries. The fact that I don't know if .trim() is a core Javascript function or part of jQuery isn't a weakness of jQuery. If a "developer" can't be bothered to consult documentation when they work on a slightly different project than they're used to, then they're in the wrong industry.

It's definitely a issue, but I think it's far from the biggest issue. If you're going to use ruby, you're going to have to come grips with the culture, which for better or worse involves more "magic" and meta-programming than, say, Python where the same power exists but is avoided on principle.

It takes a little getting used to, but once you are, then the tooling is there to help you make sense of these things:

1.method(:year).source_location

The bigger issues with Rails I see are the monoculture issue raised in the article, plus the intractable issues with ruby around performance, memory bloat, concurrency, and last but not least, the multi-paradigm nature giving you functional features, but without any of the usual immutability guarantees (unless you follow a constrained and unconventional coding style which no one does in the ruby community).

It's a fairly simple remedy, if you're OK with pulling in Activesupport