That is the message this game is clearly trying to preach, but it does not hold up under scrutiny in my opinion. The part some people are forgetting is why Joel killed Abby’s father. The motivation is not the same! One was to defend a family member; the other was pure revenge.
I condone murder committed in self-defense or in defense of one’s family. Joel killed Abby’s father and others in the hospital to save his adopted daughter**: Abby’s father’s death was Justified
**(in the original game I actually wanted to only disable the doctors to get away, not kill them; but the game took that decision out of my hands, which was one of my issues with the first game. But I digress…)
In stark contrast, Joel was not threatening Abby or anyone in her family when she killed him; in fact, Joel had saved Abby, which should have counted for something if Abby was a good person; she proved she was NOT a good person by killing him anyway: Joel’s murder was Not Justified.
I also support the death penalty against those who commit UN-justified murder, and in the world of these games, justice had to be carried out by citizens. Joel deserves justice, and Abby deserved to pay for her crime. Ellie robbed Joel of the justice he deserved, and likely she will suffer for that as well. At least if she had killed Abby, Joel would have received the justice he deserved. Ellie will never be the same either way.
Bottom line: Joel’s death and Abby’s father’s death are not the same. Abby’s father was about to kill Ellie, without her guardian’s consent, for the possibility it might save others; the doctors didn’t know for certain that it would. That is why I call Joel’s statement at the end a “white lie”. It could have been true. We’ll never know for certain. Regardless, that is probably the best ending to the saga we’ll ever get. I reject the sequel; it never happened in my personal canon.