After playing crucible and getting shredded by Clever Dragon, I went to do some strikes to try and get a Grasp of Malok to counter them. I spent all day farming strikes, and got 8 keys. I did the Will of Crota 8 times and got 1 Grasp and 7 Bonds. I have had similar results with the Undying Mind and Imago Loop farms. Bungie has clearly changed weapon drop rates and not told us.