The lady I was referring to believed if a player at the end of the row hit a jackpot, it made it less likely she would hit one. She definitely felt single coin players were ruining her chances? I don't know if I correctly identify her belief as a superstition. Let's just say she was uninformed.
I've told this story before. I once walked up to a $5 video poker machine and put in a single $20. I played single coin and hit a $1,000 quad deuce. A lady sitting next to me looked down at my machine and said angrily "Real players play to win!". I cashed out, walked to the ticket redemption machine behind her, walked back to where she could see me and counted out ten $100 bills then walked off. I guess she felt I didn't earn the money or she was mad because she was losing? I didn't give the money back.