Probably lack of capable coders.
The new skills are actually combined older animations. For example the Operative roll is a combination of Take cover and the dust animation of Force Speed. No code changes involved. Hero engine has the capability to edit and combine the allready existing assets,objects characters etc without even bother with coding. Pathfinding, AI,triggers etc also can be handled the same way.
But Bolster is a different beast. You have to mess with scripting. And Hero engine uses Heroscript, its own language.
So you need someone with knowledge of Heroscript and of course with enough time in his hands to spot and kill the annoying bugs. The only "fix" we have seen after 2,0 launch is the removal of Expertise stat from gear. So just object editing.
My guess? Bad coder or sesional coder.
In both cases I would not wait for new features like Season 1 or cross server very soon.
If you work in Software development you probably know that development actually needs to mess with code.
So unless they have these features ready since launch (like I guess they had Makeb) the more you can hope for is a new warzone.