The general situation of the cyptocurrency market is bad and that affects Steem too.
Power down value is higher than power up value, it is likely that most of the Steem obtained from power down is being sold and that affects the price.
The biggest account powering down is @ned, so @mysearchisover may be right.
I think current state of Steemit does not provide enough incentives from new users to stay and write good quality articles, and that reduces the value of the entire platform.
Dear my friend, your answer is very detailed and unfortunately very true, more of the Steemit community waves should apply to @steem-bounty and we will see for sure grown of Steem value