Politics aside, I find it interesting Dart isn't getting much traction at this point. It seems it should be in a similar position to Java during the first wave, but it clearly isn't.

By itself it's clearly not bad, it's just not better enough than what is there already to suffer the inter-ecosystem pain with native JS. Since it can't do anything JS can't the only selling point it really has is to build large JS systems in some other safer language, but we've been there before with GWT, and that didn't set the world on fire either.