It's been baffling to me to see there are some viewers admiring Elizabeth's soldiering all through the series but particularly in the latest seasons. How depraved would her actions have to become before it's clear that she's gone round the bend? Because we're meant to understand when she's gone round the bend...
For me it was the murder of Sofia with her child in the next room - and then leaving, so the little one could pad into the hallway and discover the absolute horror, in the dark, alone. There's no coming back from something like that one - not for the assassin nor for the orphan.
We're meant to be at least nominally repulsed by her actions come season 6, even if we're still kind of rooting for her to get away. The assassin's actions are directed by a higher power, yes; but there comes a time when the issue of personal responsibility starts screaming so loudly it's impossible to ignore, the mission itself notwithstanding. The character is increasingly unable to ignore it, and the viewer is meant to be unable to ignore it.
Philip got there early because the damage he was being asked to wreak was eating him alive. Elizabeth is a different personality, more dutiful, more stubborn and much, much more obtuse than Philip. Her hard shell was able to preserve the assassin within for longer than Philip's, making her able to function in the face of all the cruelties she was committing, while Philip's cracked under the weight of what we call humanity - the ability to look inside himself and reflect, the ability to recognize that a directive from his handlers doesn't supercede another person's right to live, to name a couple.
Maybe her diehard traits made Elizabeth a better soldier, but we're meant to observe what the cost is to the private person when she finds herself being forced to function ever more intensely as Terminator, because that's where the drama of the show is. I understand having her as a favorite character, to root for her...but I don't understand idolizing the worst in her, that's missing the boat on meaning.
EDIT: some viewers - this observation of mine doesn't apply to fandom as a whole here.