It's no different than listing a Java job vs listing a Scala job. There are many great developers who would jump at the chance to be hired to write Scala (Elm),

It's no different than listing a Java job vs listing a Scala job. There are many great developers who would jump at the chance to be hired to write Scala (Elm), so you might just end up with better developers who self-select to work on the shiny, new technology.