The conspiracy theorist in me wants to scream from the rooftops it's an inside job to prove the upvote | downvote thing was evil and that's why it had to go. The reality is probably more of a 4chan sees weakness and it's having fun on it.
If I take something you really liked as reddit did with the RES upvote downvote option, and removed it and the crowd turned on me, even though I'm telling you it's for your own good, and if I were dishonest, I would turn around and find a way to make you see how bad it is. So all of a sudden you have an influx of people voting up really bad stuff downvoting good stuff and boom, I can now come back to that thread of complainers and show them proof of why they can't have good things. So who's to say it's not admin bots and not 4chan causing the problems, they need proof their decision was the right one and now they have some points to toss at you on why it was a good idea, that's what I'd say if I were a conspiracy theorist. That may come across as rambling, but you'll get the jest of it I think.