Regarding Cate's comment: well I too often just accept the first thing she tells which half the time is not thought of carefully and is not what she really means but I couldn't be bothered checking the validity of what she told me.
But about my post: to be fair I did just respond to the post in question and that wasn't exactly clear in its meaning. But from the John's next post he gave his reason but I think it is in fact other way around. Putting the URL in YouTube tags with just the VideoID is actually more difficult than just posting the link therefore surely this would mean people would only put up quality videos due to the effort?
It has increased people posting videos but the quality of the video should be of even better quality than before where it was simply just posting a URL.
That's my theory anyway