|TLDR: popularize Firefox uC styles among regular users by representing them as content downloadable from AMO (just like regular themes) and promoting this 'advanced customization' as a unique feature and not something shady used only by "power users".|
One of the greatest advantages of Firefox over other browsers is its interface is highly and easily customizable, thanks to using XUL for its UI. With minimal knowledge of CSS and 1-2 hours of learning you can change almost anything you want!
Knowing that, it's weird to see Mozilla doesn't do anything about this feature at all!
For example, to install the style, you have to enable uC support (labeled as "legacy stylesheets") in advanced settings which regular users won't ever go to, then find a style on potentially unsafe community forums, and then manually "install" it by moving it to the chrome folder.
Not to mention this feature seems to never was actively developed, not allowing to anyhow store several styles, having several security vulnerabilities etc.
So, what do I think Mozilla should do:
What do you think? Hope this suggestion will get some good feedback 🙂