I think speed has a lot to do with it, last time I checked Groovy was more than an order of magnitude slower than Java, whereas Scala (which has many of the sam

I think speed has a lot to do with it, last time I checked Groovy was more than an order of magnitude slower than Java, whereas Scala (which has many of the same benefits as Groovy) was much closer. A 2x speed hit might not be a problem, but for a lot of people (myself included), 50x is way too much of a penalty when you've got options that offer effectively the same benefits with vastly better performance. Maybe things have improved since I last checked it out, but I'm not sure.