You were given an explanation in another thread. Combined with Hoda and others there will be too many gang up attacks in a row, it would be completely OP IIRC the discussion from his thread, and then the crying from the other side would be heard clear across the galaxy.
Sometimes there are decent - good reasons for when they do these kinds of things (like balance, which there finally is between the Jedi and Sith, now) and sometimes, well, there isn't, this seems to be the former
I know it doesn't seem fair or right, and the leader ability clearly shows that the synergy should be there, but OP is OP, and that trumps all these smaller details.