everything YAML-fied? [just, no]
Well the last 10+ years of software development has gone the way of "the bandwagon" so it's no surprise that something like *THIS* has become "the new bandwagon"
Meanwhile, REAL development is done on REAL operating systems with REAL tools using REAL languages and no "bandwagon". See TIOBE index which has been very accurate for a very, very long time.
/me points out that Micro-shaft tries to get everyone on THEIR bandwagon every couple of years, and then re-invents it into something else "new, shiny" and apparently abandons devs in their wake...
I can think of a bunch of stuff - windows scripting host, ".Not", C-pound, ActiveX, Silverlight, WinRT, UWP, yotta yotta yotta moving targets all. VB was *especially* a 'moving target' from 1.0. And when nobody (but a few) jumps on the bandwagon, they move on to "yet another new, shiny" over, and over, and over, and over, and over. "Here's the new version / replacement technology, get hot patching your stuff to use it, more work for YOU, no backward compatibility, you're welcome, 'new, shiny'"
I'd put YAML in the same category as all of THAT. *NOT* using it, adopting it, or even making it an option. I don't like JSON either. XML is tolerable, if it's not over-complicated [like the standard makes it - CDATA? Really?].