Not everything that makes someone a bad parent can be willed away. Someone with severe bipolar disorder or schizophrenia cannot magically cure themselves, for instance.
Some people are just not called to be parents, period. I don't see why they should become parents anyway, just to validate your choice.
As for the idea that if you are childless, no one will take care of you when you are old, I think that the way you treat people during your life is far more important. My grandmother's brother was childless his entire life- he was extremely overweight until old age and never married. But he was a pleasant man who remained close to his sister, brother and their families. When he suffered a debilitating stroke a year before he died, he had to live in a nursing home. His family and friends visited everyday, talking to him, washing him, and making sure the nurses took care of him. The nurses would comment that he was the most visited patient that they ever had. Many other patients, most of whom had children, never had visitors. A few days before he suffered a second, fatal stroke, my whole family threw a birthday party for him, a celebration of what he meant to all of us. My great uncle was a good person in life, and he was rewarded by the love and care of others. Many parents, who gave birth but were unloving or even cruel to their children, will die alone and unloved.
Ah, childless because he never married.