The main difference between exploitative play and GTO lies in the approach to decision-making. Exploitative play focuses on observing and capitalizing on opponents' specific weaknesses, adjusting strategies to maximize profits based on their tendencies. In contrast, GTO emphasizes a balanced and theoretically sound strategy that doesn't rely on opponents' mistakes, aiming to minimize one's own vulnerabilities and remain unpredictable. While exploitative play can be more profitable in certain situations, especially against less skilled opponents, GTO is about long-term consistency and defending against advanced strategies.