It happens all the time, and it has nothing to do with people destroying themselves. I'm a medical transcriptionist and I type people going back in for bariatric surgery after bariatric surgery, specifically Roux-en-Y procedures, all the time. The latest "quick fix" is a duodenal switch procedure. Many people are having this done because they had the bypass done, lost a bunch of weight, then gained it all back and then some. It's very common, which is why the point Meanie made is very valid. I don't know why they think the duodenal switch is going to work for them when the other didn't. They are just searching for the quick fix, but they don't want to make the diet adjustments they need to make.
I also know people who have had the lap band who just ignore what they are told. If you don't follow the directions given to you by your doctor strictly, you end up in a world of hurt. One guy was just sure all it took was the magic band and he could eat whatever he wanted, but the band would stop him from over eating. He ended up back in the hospital for 2-1/2 weeks after the surgery after he got sick because he refused to listen and follow the diet instructions.
Never underestimate people's desire to do what they want. Whether it's with this or other health issues. I worked with a brittle diabetic who would suck down 3 or 4 regular Cokes a day, eat Little Debbie cakes like they were going out of style, and her blood sugars would run in the high 300s at every check. She simply wasn't going to let diabetes interfere with the lifestyle she wanted.