Totally with you, not that I've posted much myself.
The sheer number of blatant links to someone else's work is staggering. I could forgive it if they made some lengthy point about a video then linked to it, but just posting a video with no comment is awful.
Then there are the serial commenters who say something like nice post, please follow me which contributes nothing. Then you see ones who try to look like they've read the post, but post an inappropriate comment making it clear they haven't. I saw a popular thread and someone had gone down every reply and replied to each saying please follow me, I'll follow you back.
I haven't been here long, but I have been shocked by the level of this. Never mind, I'm guessing they won't get that much out of it and won't stay long.