Reason Why.

Polo is not playing with the BCH.  Literally costing them $1Ms per day in fees.
Also they froze the LTC wallets.  Steemians always bitch about withdraws.
Loads of other wallets are 'in maintenance'.

The whitefish is a bit stinky!

Another reason is they might have deposited (your) BTC on Bittrex and Bitfinex to corner the market and make a killing.

I HAVE NO EVIDENCE ... but I have a strong opinion based on observation.