Even human rights are by no means god given or natural. If they were self-evident why would there have been any debate in the first place? There is still no general consent about which humans have what rights and when to rescind them. Does that make them completely arbitrary? Of course not! Sensible considerations and reasons are employed and constantly reevaluated to grant rights within a more or less agreed upon operating social framework.
You mention actual failures of the system that need to be adressed and amended but they have nothing to do with the underlying principles.