The idea was, to keep track of what the utaite did cover and to use them as a proof and to determine their upload date, also view count, also often the original description is still here (if the utaite didn't change it to something like "sorry, that I deleted this video" etc.).

While for YT covers, you can't determine the upload date from them and it's like simply gone.

And unless you cheat by useing the embed function (http://www.youtube.com/embed/YTID), you can't even determine the view count and description (a part of the description will be shown).

And another thing I believe read somewhere, is that deleted NND videos are not often/never reuploaded, but YT ones are sometimes, because the utaite delete them themselves and on YT it is usually YT who deletes the whole account and makes all those covers unaccesible?

However deleted NND videos should be marked as (Taken down on NND) on the utaite pages or (deleted) on the song pages

I see, that makes sense, logical, thanks.