1) Other than the Browns, what team that needs a CB has $17 mil of cap space to be able to fit his contract?
2) His level of play doesn't match that amount of money.
3) He can't be forced to renegotiate the franchise tag contract into a long term deal for a lower cap number. Unless he would agree to do that, no team would trade for him (See #2), plus they could lose him after one year.
It was always a real long shot to trade him.....too many things had to happen.
But who knows, maybe we'll be in for a surprise around draft time.