You always have to check yourself and make sure it'll genuinely be helpful, because it's so tempting to do :)

But that said, I had a good usecase of my own a couple months ago where a little s-expression-based DSL was just the ticket to open up some data analysis functionality to internal users without having to prematurely build out a super complex, much more rigid GUI. DSLs are really just small, hyper-flexible user interfaces. Once you frame it that way, there are many applications. (The drawback of course is discoverability/feedback, which GUIs excel at, so you have to balance the two for your usecase)