Heh, I had the same thought.
It really surprised me that the showrunners didn’t go with unCat. That was such a shock at the end of book 3, and the storyline with Brienne, Jaime, the Brotherhood, and just the thought of them pulling a Black Wedding off at Riverrun on the Freys. . . . Instead we got. . .what did we get? Oh, yeah, Jaime moping around KL putting up with crazy sis’s bullshit, Brienne moping around having done pretty much nothing except finish off a wounded Stannis, and the Brotherhood’s main characters going off on literally the dumbest f’n quest ever conceived (yeah, showing Cersei will totally make her ignore her base instincts and turn her into a reliable ally and thus unite the realms of man on Westeros against this threat. . .aw, shit, we just lost a dragon and, shock of all shocks, that zebra didn’t change its stripes).