Java (and C# and C++) have become kitchen sink sink languages. Everything is just thrown in. That makes it less productive for me. I've decided I don't want to carry around that much in my head all the time in order to read somebody else's code. I switch languages a lot these days.

Go is getting generics in (hopefully) in a few months. Some features are missing but most don't cause much pain and can be either simulated or worked around. Error handling is its biggest failure, but outside of that I find is at least as productive as other compiled languages in the same space.