I'm still using CoffeeScript whenever I can. It has one of the nicest syntaxes out there, a lot of code fits to one screenful, the logic of the code is easier to see without the clutter of unnecessary syntax and it's a joy to write too.

YAML is probably used for similar reasons.

I don't understand why people want redundant verbose syntax that makes reading and writing code harder. And sadly don't anymore expect anyone to really explain it based on anything tangible.