Sometimes humans are selfish, sometimes they are generous.
You don't like the term "systemic inequality" yet you're framing the problem in terms of our current system: very impersonal, only-the-numbers-and-ROI matters.
If you phrased it as "most of us would choose to exploit the more desperate because they have very little alternatives instead of willingly helping out" you might trigger different instincts. Instincts that would favor restricting interest rates and favoring a stronger social safety net.
There are more generous and forgiving systems that have existed successfully elsewhere in human history, so they're not incompatible with human nature, so yes, I think it's fair to characterize the American system as iniquitous.
Why should someone else's desparation and need be solely viewed through the lens of economic opportunity for someone else?