Basira and the others aren’t Jon’s ‘impulse control’ or, as I’ve see people say, his ‘link to his humanity’. Telling someone to their faces that you will KILL THEM if they continue with the things they’re doing that hurts others is not holding them accountable. Telling someone that their very existence causes danger to others and that they should avoid other people is not mitigating their worse impulses. That’s not what any of what the others did during season four. Get over it and accept that Jon did what he did because everyone around him saw him as a problem that needed to be beaten into submission. That’s it. That’s all.