#10 - March 10, 2016, 5:07 p.m.
It is not a design goal for Bone Shield to be difficult to keep up. Blood, percentage-wise, is intended to have the strongest reactive tanking mechanic (Death Strike) and the lowest preventative damage reduction (Bone Shield) of all of the tanks. That means that the focus of the player's attention needs to be on using Death Strike well to be a good tank. Having Bone Shield be relatively easy to keep afloat frees up mental space and class resources to improve Death Strike usage in an effective manner. When using Death Strike isn't the right thing to do in the next GCD, the choices of pooling resources, making sure Bone Shield stays afloat, properly utilizing Death & Decay, Blood Strike, and Blood Boil plus all of the other things tanks are expected to do is a large space to display player skill.
Haste is only devauled as described here when you achieve global cooldown saturation. Given the recent secondary stat changes and how many times we have adjusted the rotation to increase GCD utilization so far this year I will be very surprised if GCD lock is an issue outside of Heroism/Bloodlust.