In general it's true that you can't avoid the runtime, but in this case I think people's expectations are colored by CoffeeScript, which offers (for many) a more productive environment than vanilla JavaScript, with no runtime at all. Since Dart is a CoffeeScript competitor in the "languages that compile to JS" space, this is a legitimate disadvantage. Dart may well have so many advantages over CS that this becomes a non-issue in practice, but we shouldn't pretend this isn't a story at all.
I agree that it's perfectly legitimate to discuss the runtime needed for Dart, and point out that it's a disadvantage that it is needed at all, or to criticize the runtime, or whatever.
What shocks me is that people who are supposed to be techies are pointing their fingers at the runtime and making monkey noises, because they apparently have never seen a language runtime or heard of the concept. Dart did not compile "Hello, world" to 17000 lines of code; most of that code has nothing to do with the specific program. And that's the usual situation for compilers, although some specific compilers can avoid that (e.g. CoffeeScript, which is a close mapping of its target architecture).
The reason we are making monkey noises and pointing fingers is because we expected a better JavaScript, not a Java that compiles to JavaScript. We already have that. It's called GWT and this is just GWT 2.0 with a pretty name.
There's already a GWT 2.0; this is more like GWT 9.0. And as someone who has done a lot of work in GWT (and JS, and CS), I can see a lot of potential in Dart. GWT is superior to javascript/coffeescript for a certain set of problems (mostly fat-client-type webapps); a major upgrade to the language and tooling would be welcome.
