What's even worse is that Youtube has practically become self-referential in this right.
Too many times have I been linked to Youtube from another, more intelligent forum only to find myself face to face with one of those videos where some 20-something is staring into his camera bitching about (insert ideological platform here) for a solid 10 minutes, as a reply-to-a-reply-to-a-reply to a video depicting a famous speaker who -briefly- mentions the topic the 20-something is now bitching about.
Religious and political topics are the most obvious, though I once found a video claiming that PS3 fanboys where "ghey", citing a few reasons why 360 is better, which was a reply video to the same thing in reverse.
Nowadays, I use Youtube to watch videos and that's all. Occasionally I'll hop on comments to voice support for the video, though I doubt anybody reads what I write (as I pay nobody else this respect, given the state of the community).