YouTube doesn't let you appeal takedowns because there's no reason to: YouTube isn't about personal expression or freedom of speech or sharing information. YouTube is about selling ads. Who buys ads? Big companies that hold copyrights and want to be able to take down content without any sort of due process. Presumably the series of legal entanglements with companies like Viacom helped convince Google that it was more profitable to just roll over and do whatever the media companies wanted.
It's too bad there aren't any major video hosting sites I can think of that don't treat their users this way. Vimeo is the only one I know of that's theoretically attractive (you can at least pay them to host your videos), but given that they decided to universally ban the kind of content I produce (video games), I can't really try them out and see whether they actually treat their customers with respect. Anyone tried any services that do better here?