It's due to people wanting to raise their SCP rather than make a witty comment on the original to raise their CCP (I like raising CCP personally).  Thats partly why i'm saying we should all take a stand and just mass downvote them, i'm sick of Submission thieves especially.  There was a Reddit post today about a guy who had lost a lot of weight and had a shit ton of excess skin... that was posted 4-5 times in the past 6 hours, i'm sick of it really.