For me it's the comparative noise level. C# is noisy enough. When combined with stick your code here framework and code generation, monkeying with IIS, and the rest of the msft box I'm thrown into regardless of app load and requirements, I just start detaching or worse am just worn out at the end of the day. Go asks for so little in the productivity I get in return. Haven't enjoyed writing code this much since my Modula-2 days.