St. Thomas Aquanas answered that question about 800 years ago. We even have a word for it; concupiscence.

This is the original sin of the left/progressive/atheist humanist. The inversion of the truthful and correct conception of original sin, the fall, and total depravity. Where on earth did the modern world arrive at the conclusion that mankind was "basically good"? Who, after reading history, dealing ...

Sproul always used to ask people what God saves us from. They would give him a whole range of answers: sin, hell, etc. "Wrong," he would says, "God saves us from his wrath."