Yes, for the most part, cruisers are nice people. I did encounter one person though who took the cake on being obnoxious.
We were two people behind a mother a daughter (both adults) in line waiting for the MDR to open on the first night of the cruise. Note: This was traditional dining so we all had assigned seats.
The daughter went to use the restroom. When she came back, she went and stood with her mother. The woman in back of them started screaming and yelling that she was butting in line and that both of them should go to the back. She even took her cane and hit the daughter over the shoulder with it. The daughter then told the woman not to ever touch her again. Did she listen, of course not, she again took her cane and struck the women. The daughter then lunged at her but her mother restrained her. The crew - they did nothing. We saw this obnoxious woman around the ship several times and always steered clear of her. I don't know what her problem was.