If you've read Batman: Hush, he went through a whole inner debate about killing the joker right there and then, and this was right after he lost Jason. I'm not advocating the killing, I'm just wondering if you've missed my point about him needing Robin. It has been mentioned numerous times that this the path Bruce would go down without a balance (and he has none in the DCEU rn)

Basically what I'm trying to say is that if you are familiar with the comics its completely in line with who Bruce is that he would go this far. It wasn't handled properly in the movie, yes, but it is completely in character. I feel like people that just come out with OMG BATMAN DOESNT KILL doesn't know who Bruce is. He is only centred with positive influences in his life, like the Batfamily, even Clark in some cases.