I would also make the point that another way of looking at witnesses powering down is as a form of rapid redistribution. I suspect that the witnesses will be criticised no matter what they do. If they refuse to power down they will be accused of hogging Steem and trying to prevent redistribution. If they do they are accused of profiteering and collapsing the price.
The point of my post is not about the fact they are powering down. Many other people are powering down and that's their right. The point of my post is that they are currently being incentivized to powerdown because anyway the witness compensation if so high that it more than covers the powerdown and they actually increase their stake all the while cashing out at maximum rate. Cut down the witness pay to something reasonable, and witnesses will suddenly stop seeing stake as a cheap renewable resource.