Developers are ambitious. We want to build better apps now not in 6 years time when the W3C have finally moved on this or that issue. Right now webkit is enabling developers so it wins. Supporting every browser is either economically not viable or not possible without sacrificing features. If mobile firefox wants to compete it needs to step up. If developers are voting with their feet and actually using webkit features in the wild then they are defacto standards. Firefox better pull its finger out or it will die.