Mainstream is not a "moving goalpost fallacy". It was stated from the starting comment that he was talking about a "mainstream" language.
Of course the "mainstreamity" of languages is hard to determine, but Dart is so low in any kind of related metric that makes this a non-issue.
Let's put it this way: the Dart team announced a few months ago that they'd be concentrating on transpiling [1] and they won't put the VM officially in Chrome, and nobody gave much of a fuck judging from reactions in blogs, forums, HN etc.
If a mainstream language changed something, even something minor, there would have been blood (as it often happens).
Of course the "mainstreamity" of languages is hard to determine, but Dart is so low in any kind of related metric that makes this a non-issue.
Let's put it this way: the Dart team announced a few months ago that they'd be concentrating on transpiling [1] and they won't put the VM officially in Chrome, and nobody gave much of a fuck judging from reactions in blogs, forums, HN etc.
If a mainstream language changed something, even something minor, there would have been blood (as it often happens).
[1] http://www.infoworld.com/article/2902074/javascript/google-d...