I think humans think they desire good but ultimately are evil.
I think humans are essentially good, but are broken. We came into existence in the "Garden", where there was no struggle for survival, so no need for conflict. I like to look at the story of Adam and Eve being thrown out of the garden as a metaphor for both humans on the individual level and humans on a societal level.
As individuals, when we are children, we are taken care of by our parents. No need for struggle to survive, sort of like being in the "Garden". Once we eat of the "tree of knowledge of good and evil", that is "grow up" and become responsible for ourselves, we get thrown out, or choose to leave, mom and dad's house. Life becomes a struggle and we face conflict.
On a societal level, the Garden represents the ability of small tribes of nomadic humans, as must have comprised the entirety of the human population at some point, to survive by foraging for wild grown food. Back before the advent of modern language, and, presumably, real self-awareness, there was plenty to go around, living off the fat of the land. Once populations grew to a certain point, terrritories and resources were fought over, the concept of the "Garden" was lost.
The eating of the fruit of the "tree of knowledge of good and evil" is representative of the emerging conciousness and self-awareness of humanity. We began to understand that our actions had consequences, and those, in turn, had an affect on ourselves.
I think as population density increases, the struggle to choose between good and evil takes on a greater urgency, but we tend to lose sight of what, exactly, is good or evil. When threatened with existential crises, it is everyone's right to seek self-preservation, which is where we tend to compromise our pursuit of good.
It's not obvious to us that working together and being self-sacrificial is the only way we all make it through. That, I believe, is the essense of the life and teachings of Jesus, if you strip them of their metaphysical aspects. He revealed to us what it is to eat of the fruit of the "Tree of Life".
As for what God did or did not intend, I agree that may always remain a mystery. But, if you agree with the more common take, amongst evangelical Christians, on the book of Revelation, we will be facing some pretty dire circumstances before things get better.