I remember Brandson talking about this in a podcast (I believe it was 'how I built this', not sure though), he said it was his worst idea but the best name he ever had given to one of his companies. I must agree with that one!
It sounds like he thought it would be funny, and was willing to throw a few million dollars at trolling. Not hard for somebody who can throw more tens of millions at a joyride in a rocket.