I don't mind heroes that kill. I don't. Really. Whether they kill on their own, like Stark, or Strange or government senctioned, like Natasha.
I mind heroes that take it upon themselves to "carry out punishments" on the "deserving" as if it's their place to judge. It's one thing to kill on the field, it's another to punish defeated enemies. Yes, I understand his motivations. Jason's too.
But the "punishment on the deserving" concept is SO ugly to me that it overshadows whatever sympathy I may have felt. By, a lot.
By really, really a lot.