why is it ironic that Mcmurphy begins to see himself as a symbol of the inmates' right to their own individuality?

The irony in this situation can be found in the fact that McMurphy is advocating for a large percentage of men who stay in the hospital voluntarily. Many of the men don't want to leave.... they're afraid of change. None-the-less, their choice to spend such a large portion of their lives incarcerated in a prison-like atmosphere makes him work even harder to change things.