It's probably because the point makes no sense. There's no reason to go back to desktop apps, we were moving away from that and making lots of progress and now all of a sudden many are eager to return back to local desktop, but this time running inside a browser, doesn't make any sense at all.
We should be moving forward, rather than going backwards.
You're making a crucial mistake of assuming that the Web apps are the forward. Not to mention that you're forgetting that Web apps are not possible without at least one desktop app.
> It's probably because the point makes no sense. There's no reason to go back to desktop apps
Yes, there is. Being able to install a web app locally means several things immediately:
1. Local and remote storage of data beyond what traditional web apps can accomplish.
2. Snappier applications, since everything is stored locally.
3. You'll still be capable of being connected remotely.
4. Ability to use the app even if you aren't connected, or cannot connect remotely.
Also, you assert that we were moving away from desktop apps, when the opposite is true. Native apps are still insanely popular thanks to mobile devices. Even on an iOS device, you can run web apps as if they are local applications. It's incredibly useful here as well. Being able to install an application on your phone outside the App Store.
To be fair, very little of what's proposed in this project changes any of those points. You can already store data locally using localStorage APIs. You can already cache application content/scripts/resources locally using HTML Manifest files, which also let you use the application when you aren't connected to the net. And of course, you can always access remote resources when you are (even across domains using the new Cross Domain XHR technology).
The crux of what they are proposing is a standard way to actually say "I want this web site to be considered an 'app' that can be installed using whatever your platform wants to consider installing". In other words, a slightly more enhanced, standard version of adding an app to your homescreen on the iPhone.
Local storage is currently limited. On the desktop there will be means for unlimited storage. Manifest files can present more than merely what file to download (such as operating in the background). By setting the apps to a different domain, it gives them room to allow for a different permission set.
If it would become unlimited than nothing would stop my web app from filling your hard drive up with crap. So removing this limit maybe not such a good idea. Besides if Mozilla wanted to provide unlimited storage they could just remove the limit from the HTML5 storage, but they won't for the reason I already wrote.
> We already have HTML5 for that, why would we need yet another method for the same thing?
Aspects of this are limited for security reasons. Changing the location of the application, to treat it as something different, allows for different levels of security.
> Again... this is all possible with HTML5.
Again, to a limited degree for security reasons.
> Show me a recent native app that has the success rate of Facebook or Twitter.
Just look to Apple's App store as a good example. Look at all the native Twitter apps that people used over the web interface.
> A lot of native apps are just interfaces to web apps.
Yes, and why do you think that is? Because being treated as native apps gives them additional flexibility. With browsers able to "install" web apps, they can provide additional functionality to these applications that otherwise couldn't exist.
> With bookmarking them and making the app use HTML5 app cache.
Yes. So at least your aware that what Mozilla is doing isn't new. Apple's done this. Google's done this. Mozilla is following.
Couple this with other benefits:
1. Having a trusted app store where you can get your apps.
2. Allow for an easy system to setup and sell your app. Envato does this. Apple does this. MS is planning on doing this. Google does this. You also make the assumption that developers can easily accept payments. It's not that easy, unless you bow to the will of PayPal.
3. Mozilla not doing this would leave it behind. Suddenly, if people wanted to use these web apps, they'd have to switch off Firefox.
I've presented many reasons why this is a good thing. You've questioned everything, but offered little in the way of why it's bad. Might you care to offer up reasons why this shouldn't happen?
> Ohhh and let's not forget the "native" applications that in reality wrapped web apps.
Huh? Native apps that are just connect to web API's are still native apps.
We should be moving forward, rather than going backwards.