Chrome's apps are a proprietary grab at the desktop and keeping people locked into Chrome instead of being able to use open web apps in a browser of their choice. This is by design and not exactly a secret.
This is overstating the case. A "packaged app" is just a web app stored locally, with some additional APIs available. There's nothing to stop any other browser from treating the app in the obvious way, leveraging the html5-standard "manifest". Indeed this is the same way that Chrome OS and the Firefox OS of which you've spoken highly handle installed apps. If you're concerned about the expanded API, keep in mind that useful APIs are often ported from one browser to another: this is why we have XmlHttpRequest.