I loved LoU 2. I didn't experience it as a slap in the face at all. Joel's haunted limbo state made perfect sense to me given the choice he made and the overwhelming guilt he no doubt carried with him to the tragic end. An end that may have crushed fans (myself included), but played out as it no doubt would in the real world. Ellie's erratic, blind, often irrational vengeance amplified and doubled down on the sad truth that the sins of the fathers are often passed down to their children.
Whereas Joel's heroic/villainous act at the end of the first game was prompted by a father's blind but understandable love, Ellie's rampage felt like the internally logical but rash response of an angry and undisciplined twenty-something unwittingly (and ironically) encouraged by Joel's own horrifying example and unaided by his wisdom.
Playing as Abby created empathy I didn't expect, forcing me to recognize that in situations like this, there are no good guys or bad guys. It's every woman and man for themselves, driven by their own morality and sense of justice. Sad, profound, and thought-provoking stuff. The two games together are epic.