Witnesses are eating 50% of the daily reward and providing very little added value to the network in exchange. Almost all witnesses are whales, they are almost all powering down, and have zero incentives not to do so given that they are so much showered with Steem Power that their stake keeps going up in spite of them powering down at maximum rate.

Don't look any further for the price drop. Dan and Ned need to man up and explain to their Bitshares days cronies that the free lunch is over and that they have to suck up a 90% cut of their witness salary if the network is to have any chance of going anywhere in the long run. Some will quit, but hey no-one is irreplaceable, and for each Bitshares crony witness who quits, there are ten candidates among well regarded folks in the community waiting in the queue for a witness position to open.