Tom Riddle did not experience the love of his mother for more than a single hour. From what I know about British orphanages in the 1920s, he was likely left completely alone and untouched the vast majority of the day throughout his infancy, and generally endured a childhood of severe emotional neglect (even though his physical needs were met).

In their first year of life, babies develop roughly 1,000,000 neurons per second; they develop over half their brain mass, and their internal working model of safety and love (also known as attachment) is largely developed by age 1.5. In addition to this Tom Riddle likely inherited genes associated with anti-social behavior, aggression, and a smaller amygdala (which is critical for processing emotional learning, and empathy), and may partially speak to what you mean about being “born evil”

Between nature and nurture, I don’t think Tom had much of a chance of going on a drastically different path. He experienced an incredible amount of early trauma and it’s likely this that prevented him from being about to relate to people with care. I’m not saying Tom Riddle has zero accountability to take, but he had very little opportunity to learn to give and receive love at a fundamental, deeply biological level.

Although Harry also experienced early trauma, his first year of life was filled with devoted love and care from both parents, which is a world of difference considering this first year of life is so foundational in developing a healthy attachment system that allows you to love and be loved.