Where WebOS got it right: Text-based UI layer and applications

Taking advantage of the demise of HP webOS hardware venture, an orphan tablet and phone reached my postbox recently. As a traditionalist computer geek, I was interested to live the so-called post-PC experience using the beloved webOS.

The two form factors hardware feel robust and nice to handle, notably the perfect balance of usability and portability of the Pré 3.
The user experience is as enjoying and intuitive as stated in reviews describing it in great length. Thus, I wont detail it further.

The active applications developers community  is surprising for stray dying platform. Both official and homebrew channels provide maintained software. Firesales and quite flat learning curve broke barriers. Somehow they did something right here.

Fixes and extentions to standard shell and applications are distributed by Préware.  Being defined as textual data, easily diffeable and patcheable, the environment is simple to modify and extend at runtime location. The Holly Trinity HTML/CSS/javascript makes fiddling with the system accessible to casual developers.
Applications, both system and third-parties, are actually editable data.

The Shell's javascript nature and its you-shall-do-what-you-want extensions mechanism, dynamic languages bindings, GtkBuilder and CSS-enabled Gtk+ tend to offer the same advantages to the Gnome platform.
Though, modifying core modules (mailer, contacts directory, web browser, to name a few) ain't a straight-forward process. Furthermore, patches packaging is not supported by major distributions provisioning services.

Making the whole environment patcheable in-situ without restrictive extensions points might prove fragile and error-prone but offer a freedom rarely seen even in free software. Preware packages supports patch reversion in case of issue or change of mind.
In the interim of having a common extension mechanism ala OSGi and robust well-defined extension points, local-patching might catalyze the transition from user/applications developer to contributor. Editing a system file and creating a patch is a fast process to create a deviation from a base system compared to getting the source, editing building and packaging.
Proposed patches for distribution should be deeply reviewed to enforce compatibility, security and quality.

In a read-only base system future, patches could be deployed at boot time using FS overlays as found in Fedora USB image, ZFS or Btrfs. Or why not a system-wide git repository ?

What's your take ?