I dont like when it is implied that a tool is better than existing similar tools because it uses language X (it is, but only fir X enthusiasts) but I want to see the language somewhere on the site front-page. I use an unpopular OS (FreeBSD) and compile a lot of applications from the sources and if I have a toolchain (an interpreter) for a given language installed I may try a new application, if not especially if this toolchain is heavy I would need a stronger motivation to try a new app.