Apple is the largest company, by market capitalization
By that argument, aren't GE, Exxon, and Walmart all bigger in IT than Apple?
Apple is not big in corporate IT; they are big in home/consumer devices. I work as a software developer at a major IT company. The only Apple products I see at work are the personal iPhones that employees carry. What this means in terms of the direction of standards is questionable.
In the last few years I've spent roughly as much on home IT hardware as my employer has for my use at work. For the first time ever, my personal dollars went primarily to Apple. Due to a beautiful UI being crafted on top of BSD, Android not being ready for prime time when I wanted a smart phone, and XP being overdue for a major overhaul when I needed a computer.
I think I'm done with my Apple binge. Android is ready, Apple laptops and desktops while nice, are overpriced. Apple has benefited greatly from Windows Vista/Windows 7 and Android product cycles.
In this case I think Apple is right to limit the demo to Safari, because at this point not even Chrome works for all the demos. I don't like everything that Apple does, but in this case what are they supposed to do? Due to no standard being set on video, no other browser will properly render the demos. I do question what the deal with the CSS is. Remember, this page is a showcase of Apple's products based on the not completely baked HTML 5 standard - it is not a general HTML 5 showcase:
If we are to accept what you say then the following can't be true:
Standards aren't add-ons to the web. They are the web. And you can start using them today.
Standards aren't standards if they're not standard.
Make it right before you make it faster.