I think this has been addressed several times, the performance issues for video playback are Apple's fault for not providing the necessary APIs to allow third-parties access to hardware decoding (which exist on Windows). In 10.6.3 I believe they finally added them, and Adobe released a beta/alpha of Flash player that uses them.

Then, there have been several benchmarks released recently showing that Flash is faster than HTML5's canvas for drawing, both on desktops and mobile devices.

So I think your comment isn't exactly fair, or at least it deserves some qualification.

(Note: I am not an Adobe apologist. I barely use any of their software, and have no personal stake in their survival. I'm just seeing Apple spreading a lot of FUD and that upsets me as I've been a big fan of the company.)