Actually, thinking about it, it does! "People under people" is a metaphorical description of a business, and they "exploit capitalism", that is, use it to their advantage, selling products and living off the profit.

But, of course, that is not what the joke I quoted means. What it means is that, like Churchill's alleged saying about democracy goes, "it's the worst system except for all others". So far, anyway.

He probably meant that "people exploit people" phrase should be put the other way around, concluding that there's no difference in this aspect between capitalism and socialism at all.