The reason that I keep recommending the Booker T. Washington address, is that it humanizes the interaction. I suspect that there are very, very few, today, who ever went weeping to a cemetery to mourn the passing of the person in charge of a local Welfare Office.
On the broader subject, one can cite Biblical relationships; the celebration of British valor at Agincourt, or whatever illustrates the fact that Mankind has always had to struggle with the fact that everyone does not achieve at the same level, and leadership to address the resulting "problems" cannot be fairly judged without a better understanding of the "problems," than those trying to prove points are likely to have.
William Flax
Now maybe some research is called for, but I'm betting if you were a single slave with no family or relatives, you might be bounced through the system from one owner to another. Maybe you wouldn't actually be turned out to starve, but the notion that your masters would be extremely benevolent when you got to old to work is something I'd question. Having children and other relatives on the plantation that you could do things for and who could do things for you would probably make a master much more likely not to sell you off.
In any case, when emancipation came, many slaves took to the road. The conditions they found when their journey ended may not have been very different from what they left, but they very definitely wanted to get out from under the personal tyranny of particular masters and live their own, more independent and self-reliant lives.
It's funny how some people who are most adamantly for liberty and against government have a soft spot when it comes to the tyranny of slavery and make the same kind of paternalistic arguments that they spurn when it comes to present-day society.