For me, it was a combination of the devaluation plus lack of any real promotions that drove me away. There was really no competition this year when it came to comparing promotions from Hyatt, SPG, and HH. In a bad economic year in which I had much less travel than before, I had to put my stays with Hyatt and SPG in order to get the best value because of their promos.
I planned on returning to HH more when my travel picked up again, and other programs' promos went away. However, I really dont see a need to return now with the point structure changed so much, as I still get more value out of my stays at other properties. Offering better and more competitive promos, even with the increased redemption amounts, would bring me back. I just won't put up with both increased levels and lack of good promos.