I don't want to deal with 2 different package managers and new users are apt to be confused by the idea that they get packages from 2 different places.
Look at Android and MacOS. You have these self contained packaging things that contain all their dependencies. You have the same dependencies in each package. You have a TON of wasted space with packages that have the exact same built-in libraries and jar files.
Especially with Android, they could have made a real package dependency system, with slotted installs of all the jar/jar-versions from the official maven repos. When you install and app, it could install all its dependent jars. You'd still be able to do multiple versions of each of those jars, probably easier than it is with standard .so/.dll libraries.
Projects like this are a huge step backwards is terms of DRY principals and general package management.
I am not sure if the whole jar package dependency management would work under ART.
In the end something that ought to have taken 10mb of space and 20mb of ram requires 100mb of space and half a gig of ram and still manages to be slow on a new system at operations that ought to have been fast on a ten year old machine.
Down with the Javascript generation.
I hate to use any of these chrome-"native"-packaged-webapp, though. I just hate java based GUI apps more.
Android also runs on phones that still mostly have less storage and less RAM than our desktops, so you'd expect saving space to be even more important for Android.