It has no big boobytrap for beginners, on simple enough patterns it looks very clean and simple, it allows comments while being easy to convert to JSON. I thin

It has no big boobytrap for beginners, on simple enough patterns it looks very clean and simple, it allows comments while being easy to convert to JSON. I think these are the main things that push yaml. In particular, being clean and simple for straightforward data is a big plus: configurations are often just key-value lists of ver small strings, having something that is readable and looks simple helps a lot. And for anything that needs more finesse, switching to XML or JSON is often supported.