I believe I understand why they didn't do anything - it's because people are crazy, and unless you are prepared to 1) physically defend yourself and when you do defend yourself, be prepared to most likely 2) be placed in the brig and 3) not allowed to cruise RC ever again, you let management handle it.
My group witnessed something awful on Independence, while waiting for the MTD person to call our reservation number. There was a medium-sized guy, not super built but somewhat built who was vocally reacting to each reservation called with some sort of comment. He was unhappy that he was having to wait. Comments like "Lies!" and "They are lying." were flying around. We tend to think he was overserved as well.
An older woman (I'm 62, I'm guessing she was somewhere around my age) confronted him. She was sitting on on of the couches/seats outside the MDR, and in a calm voice, she said something like "Now, that's enough. You've said enough". This guy said "YOU GOT SOMETHING TO SAY TO ME?" and stepped over to her and punched her in the face. To be quite honest, I witnessed the comments and behavior, but our number had just been called (LIES!) and a server was taking us to our table. As soon as we started walking, I asked the server if he could call security, and he said it was being handled, but I did not see the punch, I asked for verification regarding the woman being punched from a couple of the servers and they confirmed that's what happened.
I remain stunned. I trained in martial arts. I am older now, but could maybe still defend myself, but who would ever think some drunk jerk would punch an older woman in the face ...
While hindsight is 20/20, I'm thinking I would have requested to be seated elsewhere.