I'm quite happy using a preprocessor like [0], which keeps the great simplicity of JSON and just allows comments.
[0] https://www.npmjs.com/package/strip-json-comments
I don't, actually, I use preprocessors too¹, but since they're not always an option, I'd rather recommend yaml than have yet another pointless config file language needlessly fragment the market.
¹: Thankfully it's rather trivial in python: https://github.com/creshal/yspave/blob/master/yspave/pave.py...
I'm quite happy using a preprocessor like [0], which keeps the great simplicity of JSON and just allows comments.
[0] https://www.npmjs.com/package/strip-json-comments