User blog comment:Xilinoc/Ch. 619 - The Betrayer/@comment-24531362-20150314014322/@comment-5398287-20150315195723

Well, the situation was a bit different the first time around. While Uryu was indeed standing next to Yhwach and firing at Ichigo, Ichigo knew about how Yhwach killed both their mothers, and probably thought something along the lines of "oh, he's probably infiltrating the ranks to attack Yhwach while his guard's down or something", which was Uryu's original plan, and which was supported by Uryu telling him to stay back from Yhwach rather than going for the kill. This time, though, Uryu outright shot one of his friends in the shoulder to allow Yhwach to resume killing the Soul King, which started destabilizing reality again, which is a big step up from "I'm trying to protect my friends and do this alone", so Ichigo's understandably confused and angry now.

Also, I doubt that this'll turn into a Kaguya situation; aside from the Soul King himself, there's no one "higher" than Yhwach that could have been manipulating him, and unless this whole "being murdered by your own son" thing is secretly a way for the Soul King to become more powerful and regain his limbs (which could honestly make for a decent twist), I can't think of a reason why he'd be manipulating Yhwach to do all this.