You said something quite different sounding than here. Here you mention systems to prevent mistakes. Your original post said

    you aren’t allowed to make mistakes of this magnitude. It really is that simple.

That does not mention prevention systems and instead put the blame squarely on the person making the mistake. They "simply should not have made the mistake, duh!"

Someone has allowed some crap systems to exist by the time something like this happens.

You’re right that my initial post makes it sound like I blame one person, and I sort of do. However it isn’t the guy who didn’t close the hatch. I blame the command structure and those at the top of it.