Much like android dart is controlled by a small group of engineers in Google. Where's the source code to the current HEAD of dart? I'm pretty sure it's not on GitHub. What features are planned for the next release? I'm fairly sure dart-discuss doesn't exist publicly.
Dark doesn't belong to the web developer community. No conspiracy theory needed, dart is built to suit googles purposes, which is fine. The only thing is expecting people to use it and think its a successor to JS, which, for all the flaws of JS, it is not.
Google know what a community developed successor to JS looks like. Optional strong typing in even MS typescript is more popular than dart. Get together with the community or dart will be he next GWT.