In my opinion this is a smoke screen from Poloniex. No one has problems transfering Steem except them. They have 24 million tokens in their wallet which is almost 10% of the total supply.
Unfortunately other services such as Changelly and Shapeshift use them to execute trades.

Ask yourself this question...If you can transfer Steem to anyone else why can't they?...I say bullshit.

At best they are incompetent.