The main focus of jQuery Mobile is NOT to be a competitor to native apps written in Objective C or even Sencha Touch. We aim to build touch-friendly UIs based on HTML5 for web apps and websites that are easy to build and work across a huge variety of platforms.

Sure, you can wrap a JQM site into an app with something like PhoneGap but I agree that a native app will always be more "native" and perfomant.

People never compare web apps built with jQuery UI to native applications created for desktop platforms, so it's a bit puzzling when we see developers try make comparisons between apps built with jQuery Mobile and Objective C. They are completely different tools, each with pros and cons.

The emphasis of the project is on embracing the web for mobile and I think that is the best way to judge the success of this framework.