The Watchtower Society is simply a legal Corporation used by Jehovah's Witness Leadership for various purposes. Mock it all you want, it is not morally wrong so to do, but I think a bit pointless.
I think it is wrong to mock individual JW's, even if they are our own family perhaps, they are simply in a place that we were in not so long ago.
Now, when it comes to the beliefs and practices of the Jehovah's Witnesses as a group, or religion, if they deserve to be called one, then I think it is a Moral Duty to mock, deride and lampoon said beliefs and practices.
No silly beliefs deserve any kind of respect, and satirical and humerous attacks upon such things are one of the best methods of waking up the practitioners, nobody likes to be perceived as silly.