I think part of it is that back in the 2000s and 2010s, most KU setups delivered (March 2018 is a great example), and now we're seeing some flies in the ointment. sure, some of those failure modes are popping up more and more because of CC, but I think we got a bit spoiled, so now a block pops up and everyone expects a KU (I am personally guilty of this and am trying to remove this bias)
mid-Feb easily could have occurred, the ULL just became a bit sloppy and the system became more disorganized... it still delivered historic snow to VA beach, and there was also a once in a lifetime Gulf Coast storm