My impression from this post (as someone more familiar with Java and Python but who has tried Ruby a bit) is that it's a complex, fast-moving ecosystem that's somewhat difficult to keep up with. Not a bad thing, but a bit daunting for people who don't do it full time. There are other fast-moving ecosystems that I already have to keep up with.

It likely has the side effect that that web searches will bring up a lot of obsolete articles.