What was the point of Firefox? IE was free and was a proven and already well-established browser. By your logic, we never should have built Firefox and the Web should have stalled with IE6 in 2002.
The world needs a truly open mobile OS as much as it needed a truly open browser a decade ago. Android is open in name only and Google is hurriedly moving its most lucrative components into closed proprietary services and apps that aren't a part of open source Android. iOS is as closed as everything Apple does. Windows is getting some nice HTML5 support for apps, but not nearly enough. There's clearly an opportunity for HTML5 apps to compete on mobile if someone can build a solid alternative platform to the monopolies and silos we're all stuck with today.