Because before being a meme it's someone's creation, and their creation is being used for nefarious purposes that they don't condone, art has always an artist behind, a human. A meme doesn't appear out of a vacuum.

They can be authoritative in their intents and try to seize back their creation, as fruitless as this will be (and the author very likely is aware of) I think that's pretty sensible of them rather than throwing your hands up in the air and let the chaos machine of internet meme culture take over everything it touches.