Tim O'Reilly's talk at Velocity 2015 discusses the importance of not treating workers merely as cogs in a machine, emphasizing the need for a culture of optimization that empowers employees. He contrasts traditional workplace monitoring, which can create a culture of fear, with modern platforms like Lyft and Uber, which provide workers with agency and data transparency. The talk concludes with a call to use technology not just to replace jobs, but to enhance and upskill workers for the challenges of the 21st century.