Apple developers need to sign a NDA with the creation of an developer account. These videos are under NDA cause it is beta software and confidential. This is the reason why you need an account to watch those videos.
BUT even if they weren't under NDA this is totally ok! Going to the conference would have cost you minimum 1 week time and >1500$. You get all of this for free after only four days the conference happened. The only thing they ask for is an account and you are complaining about this? I will never understand such attitude!
Neither have any of those. Just because everybody does it (require registration), does not automatically make it good and ok. Sorry, you can downvote me if you like.
Yeah, RIM has the same requirement when you try to view content from their developer conferences (DevCon, Jam, World, etc.). It is an issue that BB developers have clamoured for the removal of too.
However, the actual documentation and tools don't require an account to access. Just conference content.
You'd be surprised. They might have some videos and material for free (as does Apple, btw), but lots of other development stuff from them requires an MS/Google account.