I suspect (because I read minds) that if they _knew_ Go was going to add generics and such in a year or two that they'd be ready to dive in for a big project or two. No point in investing the time in working up a significant Go project if you value Features X & Y but don't believe the language is headed there.

In other words, the frustration is because Go is _close_ to a good language but not quite good enough if we know this is it. Or, maybe even worse, we don't know anything at all about its future direction.