Relentless employee complaining

I am currently in the transition of a job change, and I find that our day shift employees are relentless in their complaints about everything from the response time of the call tracking application to the customers calling in for assistance. This can be very depressing. I question their current supervisor, and her comment was thier venting thats all. I wonder what it would be like to listen to this day in and day out, and I have come to the conclusion that I would have to work else where. I have never heard such discontent in my life time. So the question is how do you change that around? I would love to tell them the story of “I use to complain about my shoes until I saw a man with our feet etc, etc, etc……”, but I figure I would be precotious. Any thoughts on the subject?