Shows why humans are not responsible enough to colonize space. This 4 billion year pristine environment now trashed by the good old us of a. You'd think these clever people at NASA with their limitless budgets would figure out a way to clean up their own junk, but no. Not a priority.
It's not just the US (wasn't even first). Anything we humans have sent to the Red Planet that touched the surface (landed/crashed) is still there. We barely know how to get there and are still trying to figure out how to get anything back.
It's like telling a three year old to clean up after himself; not likely to happen. We're just not "old enough" to know how to.