The weak are not responsible for their actions. They can rob, kill and rape, and still be excused for it . They can blow up buildings, behead prisoners and get sympathetic nods. Because they had no choice.
Weakness is helplessness, it implies irresponsibility because the weak are not capable of making their own choices. Their choices have been made for them by the "Man", the "Patriarchy", the "Privileged" and the "Military-Industrial Complex"-- all different names for the defined power structure and the people who are responsible for it.
Since the choices have been made for them, they have no choice but to lash out. When they kill, it is not an action, but a reaction.
To the people being raped or murdered by them, the ones jumping from buildings and coming to claim the pieces of their children at the morgue afterward, they do not appear to be helpless at all. But that is only because the people being raped and murdered, and waiting to identify a small can of their child's remains are privileged. So privileged that they don't know how responsible they are for the state of affairs which caused them to be raped or murdered. Which caused their children to end up in coffee cans.
Even when they are being raped or waiting to die, they are still the strong and the responsible, and their rapists and murderers are the downtrodden and dispossessed. The weak who are so helpless that they cannot help but seek their source of strength through violence against their oppressors. And if those oppressors happen to be women and children-- well then as the left has said from France to Russia to New York to Israel- "Power to the People". The "People" being the ones doing the killing. The oppressors being the ones doing the dying.
Weakness does not always translate into such extremity. What it translates into is irresponsibility for the collective burden of guilt that the left hangs around the head of every society. The responsibility for the poverty, the bigotry and all the inequities that are said to spring from it.
There are no more personal failures, whether economic or marital or ethical, only collective ones-- and the strong are responsible for their own failures and for everyone else's, while the weak are not even responsible for their own failures.
On the collective scale, choice is nearly irrelevant. Only people with power have choices. The idea that the man waiting in the alley with a knife has a choice is a heresy because he is not a man with a knife, he is a collection of social statistics which assign him an automatic level of responsibility based on his race, gender, socioeconomic status and all the other variables. Whether or not he stabs someone with a knife, is not up to him, it's up to how society treats him.