Well, we can change soils and have had to be doing so since the fall and are still doing so.
So, if you want to say we can't change hearts, then you'll need a different analogy, or just cut out the analogies and say we can't change hearts, and we can argue this.
I'll start with practical experience. When I was a kid at some point in early advance through school, I got lazy and rebellious and my abilities to understand suffered. One night my mother decided that was enough and forced me to sit up almost all-night studying and practicing for an exam the next morning. It was brutal as I recall for that young age, and I had near zero thought or will that I could do what was being tested. I got taught and drilled to exhaustion. I got a few hours of sleep, was forced to go to school, sat there in trepidation for my name to be called for the oral exam, got called, was shaking, aced it and on the clock the fastest in the class.
Our heart condition starts very young. There are many stories of parents and teachers and other caring persons who make differences in the hearts and minds of the young. Our Text speaks of people hardening their own hearts and this is the prelude to the parables. God maintains harsh penalties for teachers and leaders and gives instruction re: rearing children and working the rebellion out of them as He does with us once we are His.
I simply think we should consider our role in our lives and those of others around us when we're talking about conditions of hearts or soils by analogy. We have little clue what we're going to hear at the judgment and at what He will not address that He could have.