I think to be fair this game isn't being released under the famous statement of "When it's done". They haven't proven it yet in their BWE's. The last one they changed the skill tree, so that is some late cold feet for sure.
Someone a top came down and told them... here's the date. And imo now they scramble. It's not in terrible shape, but this beta was nothing like the pure elegance of GW1's betas. They are still working on getting the GPU to handle more of the load to get proper performance.