The point of this (Ubuntu feature) is not that it's integrating proprietary Ubuntu services with the OS (it has already done that, with Ubuntu One), like your example of Google Music, the point is that it is promoting web applications to first-class citizens alongside the native apps. Android fails at this pretty badly.
"web applications to first-class citizens alongside the native apps. Android fails at this pretty badly"
Android isn't "failing" at something that it isn't trying to do. Web apps generally suffer from low performance when trying to do anything moderately complex on a mobile device. If you must use web technology to create apps on Android, there is webView in the sdk for you. Many web apps that have tons of users like Google Maps, Pandora, etc. have native apps that are actually performant, follow UI conventions, and have access to all the APIs.
You're missing what's right in front of you; the fact that web apps suffer from bad performance on Android is a prime example of how it is failing. Perhaps Google doesn't care about web apps, but that would be a huge turnaround from just a few years ago when it was one of the web's biggest proponents.
I think it has less to do with this and more to do with them not focusing their efforts on that front. It isn't like their current dev stack is the pinacle of performance either. Give it a few years and I'm sure they'll have native Dart applications which will be just as performant.
I have an iPad and web apps suck on it too. What is your benchmark for good performance? I'm being serious as I'd love to be able to have a legitimate mobile outlet for high performance web applications.
I think the best example of this is Windows 8, which has 2 application environments, .NET and Trident (The IE10 rendering engine). They are, for all intents and purposes, on equal footing with each other, and an end user can't tell which environment an application uses.
The engine that powers it is exactly the same, the difference is additional APIs (that add functionality, not performance). Everyone already agrees that HTML/JS needs more APIs.
