I'm not claiming the youtube interface is not functional, I'm claiming it's ugly. It's not about whether interface elements are animated or not (I am criticizing however how hard it is to make them move). And I understand us techies like a really simple design. The difference is that I don't see the world as sharing my opinion. Simple websites are good for various technical reasons, and I understand that. Scraping them (not that ggl makes it easy), interacting, using the website as an API, all things that matter to techies.
But let's be honest : they're ugly. Youtube, for example looks like an ancient file manager, at best.
Let's compare, a native application with a -somewhat- similar purpose versus youtube.
XBMC: http://www.youtube.com/watch?v=34h_sQ7-G1s
TiVo: http://www.youtube.com/watch?v=GNvgoLVzijE (I realize it's an irritating commercial. But look at the interface)
Netflix on ios: http://www.youtube.com/watch?v=F-4_ADXYT3E (sorry about the reviewer, and already much worse than XBMC or TiVo)
Youtube: http://www.youtube.com
This is a very nice animated interface (imho): http://www.youtube.com/watch?v=vCw0eWa-LkA (not related to videos though)
The sad part is, that you're right about Youtube as compared to some of it's online alternatives. Compared to those, it's not bad. But the whole point was to criticize online development tools like HTML and Javascript, as compared to offline ones. Flash versus HTML and the quality of interfaces they enable.
I would even go so far as saying that, when it comes to native apps XBMC and TiVo count as "good". They don't quite match my standards for "great" at all. Youtube ... euhm ... is at the level where I'd have trouble accepting it from a first-year programming student. Certainly wouldn't merit an A.