I'm with you, I think that Dart is very sensible and very underappreciated language. But he does have a point in saying that currently Dart is tied to Flutter. Google is presenting Dart as a language that you write Flutter with, not as a separate entity. I'd much prefer if Google would present Flutter as a GUI framework for Dart, but alas. Perception is everything. As much as I'd love to start my next project in Dart I probably won't because I can't be sure that Dart won't end up in Google's graveyard in next couple of years whereas I'm pretty sure that Go won't.