I don't see it that way. This is a good example of using a tool that is proven to do what it does well (coffeescript) and also assists adoption by allowing some

I don't see it that way. This is a good example of using a tool that is proven to do what it does well (coffeescript) and also assists adoption by allowing someone to play with it easily in the browser. You dont need a whole other runtime to run the outputted PHP either, its a developer tool - are you saying if all of your developer tools are not written in the same language your programming in that is a slight to your work? I use jetbrain's rubymine to write rails apps, should I think it is a smell that my ide is not written in ruby?