The guy also said the iPhone's resolution was comparable to the Motorola Droid, but the iPhone 4 actually has 50% more pixels than the Droid.
If the demos suck in all other browsers Apple could point to that and say "Hey, told you so.
That's not the message Apple wants to send. If you're trying to promote HTML5 and terminate Flash, what you describe would be a stupid message. All people would say then is, "Clearly I'm not ready for HTML5. Just let me continue with Flash."
Since there is no way I can test them with Firefox I do not know whether they really "look like crap" there.
Poor baby! If you care, you can download Safari. If you use Linux, try the demos on the developer page in Google Chrome for Linux. They work in Chrome for the most part.
Never let someone who says it cannot be done interrupt the person who is doing it.