> Without having installers that include adware (Java)

Only for developers that aren't savvy enough to know the multiple options to bundle the runtime or compile to native code.

Or the users that don't install Java from http://www.oracle.com/technetwork/java/javase/downloads/jre8... or can't be bothered to read a dialog box.

> or that seem borderline-unsupported (X11/Quartz)

Since when is Quartz unsupported?

> or that require funny multi-stage compiling (Qt).

Since when do users compile GUI frameworks?

Cross platform UI is nothing new, there are much more options to choose from than those you listed, and browsers can hardly offer more than a 90's GUI experience.

> Since when is Quartz unsupported?

I think he was referring to X11.app — aka XQuartz — which has not been supported or included in OS X since 10.6 (Mountain Lion).

Qt only requires funny multi-stage compiling in C++. If you use it from Python it all just works.

And there's no reason someone couldn't create similar bindings for atom/node/iojs etc...

But that means the technology is being chosen to suit the developer, and not the end-user.