The long power down time is actually a disincentive to keep Steem powered up if all you're doing is speculating on price. With only 3 days to power down, you get the best of both worlds. It's long enough to prevent panic selling and short enough that speculative players may be interested in powering up when they weren't before. This should serve to increase the value of Steem. That is, if Steem is still around for much longer. It should be interesting to see what Mr. Tron does now.