You would think that if they truly believed their message was benign then they would be happy to give it the widest exposure possible. The fact that the videos are removed shows that they know that the message is unpalatable to the mainstream viewer and even to a JW if it is not accompanied by the positioning statements that the watchtower gives.
Because these unauthorised postings show the videos for what they are they have to be removed because the message is not being controlled and the viewers are not being told what to think before they see it. If you remember back to the Sparlock video even witnesses thought it was a spoof video because seeing the message without the wrap around of doctrine and thought control simply made it look ridiculous.