Few issues are completely one sided, but slavery is about as close as you can get. That roof over their heads is just cheap rationalising to help the masters feel good. Like patting yourself on the back for feeding someone a fish today, when you could have taught them how to fish but you won't because you want to keep control. You even go as far as stopping them from figuring out how to fish on their own, on the notion that they can't handle such dangerous knowledge. Slavery wasn't even really good for the plantation owners. Their world view was seriously warped by the prejudice they ingrained in themselves. They really believed their self justifying propaganda about blacks being inferior, latched hard onto the whole idea of the White Man's Burden. Laboring under such wrong thinking leads to systemic weakness.
The ultimate reason the Confederacy lost was that when they started the war, they were already way behind economically, and that was thanks to slavery. Slave powered economies simply are not competitive. Very static, resistant to change, and lacking innovation. They deluded themselves that southerners were more manly than northerners. Hoped that, a few other advantages like King Cotton, and most of all the advantage of being the defender would be enough to tip the scale against the Union's huge numeric advantages. But often their leadership would squander the defensive advantage by making reckless assaults, possibly out of that misplaced sense of greater manliness. Lots of battles in Confederate territory have more confederate than union casualties. General Hood was the ultimate in reckless aggressiveness, and President Davis put him in command because he wanted aggressive action. The result was that Hood got his army killed, first seriously reduced at Atlanta, then finsihed at Nashville.
What I don't like is the "blame the victim" angle of this data mining. Instead of this approach of mitigating things the consumer did, as if they might be bad for our health, why not grill the store? Like, instead of haranging the consumer about a pizza they ate, what about a talk with the pizza vendor for using too much salt or fat or whatever? One thing that the US does is pour way too much salt on our food. There is precedent. I think bars are legally constrained not to sell alcohol to someone who is drunk, and/or required to prevent them from driving away.