The victim in your knife attack had the opportunity to leave by never going to the grocery store. The fact they couldn't foresee that attack is solely because they lacked the information or cognitive ability to foresee it, just like an 80 IQ gambler with a Draftkings account lacks the information/cognitive ability to foresee the attack on him.
So many people walk around with the implicit ethical system that 80 IQers don't deserve to have a decent life in the modern world. That is obviously despicable once it's stated explicitly.
Many of us experience that knife attacks are not part of life, but perhaps we take for granted the existence of scammers?
Granted, being able to protect against one self against a scam may include talents that carry over to other useful aspects of society building, but same with being able to fight off knife attacks
And again the point is that, 1: those aren't the only beneficial aspects to society. someone without those talents may be brilliant in other ways, thus evolutionary pressure on that is not helpful. And even if someone isn't brilliant in other ways, we are all still valuable. Just ask a parent who raises a highly disabled kid, they will know this far more deeply than you or I do
I do not agree with that statement. You're just justifying anti-social behavior.