Interesting.
What really makes Bittrex worth blacklisting for me isn't the why. The fact that they disabled user accounts without a timely warning and how they went about it is already a mistake that reflects poorly on the company's concern for customer relations.
As for their response, it's a typical dodge. Not acknowledging any wrongdoing or responsibility and they even hint at it happening again. For my own peace of mind, Bittrex is out.