These aren't good changes, I'm sure there are way more qualified people than myself to give more details and scenarios but here's the gist. Drk isn't hurting for DPS more than any other tank is, Drks main issue has nothing to do with its contribution to raid DPS. Also, with the tank damage nerfs no one is factoring tank damage into their DPS checks as much as they did previously since tanks have to focus on mechanics and staying alive nowadays.