> Well, neither can H.264 be a standard
Let's not split hairs. Browser != data format.
I can see the point you're arguing (or at least what the author is trying to argue, whether or not it's your opinion as well). But it's at best a stretch.
In the IE6 "glory" days, it wasn't just a case that Websites wouldn't be made to work for other browsers (meaning they were never tested or, if they were, it was beyond scope to fix). It was worse than that. Sites would deliberately look at the user agent and simply not work if it was a non-IE browser. This still happens. I still come across sites that not only warn you they're optimized for IE and FF (ie proceed at your own "risk" when using Chrome). Some go further and simply won't work if you try and use Chrome. It's thankfully rare but it still happens.
Anyway, the point here is the IE6 displayed HTML/CSS content differently than other browsers and had JS differences too. It took effort to make things cross-browser and it was (and arguably still is) a big deal.
So the stretch of comparing H.264 to IE6 is twofold:
1. We're talking about the entire Web vs the narrow context of Web-based videol so it's a question of scope; and
2. Converting video from one format to another can be automated. Converting a site designed for IE6 to work on other browsers cannot.
So not only aren't the problems analogous but the author is engaging in scaremongering to try and equate H.264 with the (stipulated) horrors of IE6.