“Anyone who slaps a ‘this page is best viewed with Browser X’ label on a Web page appears to be yearning for the bad old days, before the Web, when you had very little chance of reading a document written on another computer, another word processor, or another network.” – Tim Berners-Lee (in Technology Review, July 1996)
It's browser vendors that are bearing the torch of interoperability and standards compliance. Unfortunately, most vendors are companies with their own agenda. To add to that, all companies and people interpret standards differently. Given this, it's no wonder we don't see consistent api implementation and behaviors between browsers.
The aftermath of all of this falls on the developer's shoulders, which is why so many hours are poured into getting a modern webapp to work across all browsers. Resources are limited, and at some point, developers have to throw their hands up and resign from having support across all browsers.
When you start using a seemingly mature HTML5 api, and find that it doesn't work as expected in all browsers, what recourse does one have? Should we continue to stifle innovation while we wait for the browser vendor to reach compliance? History shows you're going to be waiting for a while, or for ever.
One option is to ensure that functionality you're relying on can fall back if the feature isn't enabled. While that's not the hip-and-cool thing to do, it is a very valid option and doesn't take considerable time if it's a goal from the outset.
