People despise running because it has taken away their sense of freedom, joy, and glee. When we look to children for inspiration, we see this mindset at work. Children constantly run; we tell them to slow down and take it easy. We restrain them. We despise it when they run with awe and ecstasy.
Because there is no money or real fame in ultrarunning, it is a fairly pure sport. As a result, people who run long distances do so because they are drawn towards the pure feeling.