drinky: maybe.
I think it's not fair to assume people are fat just because they aren't trying hard enough. It's like assuming I'm not in the NBA because I just didn't practice enough, or that Cyanista isn't a full back for the Saints because she just didn't put in the hours.
Some people are physically more capable than others. This includes things like athletic ability but also things like cholesterol level, insulin resistance, metabolism, hormonal environment, brain chemistry, and the like.
Some people have better life situations than others. Maybe they have a better support network. Maybe they are more financially independent (income and obesity are also correlated...lower incomes tend to be fatter).
Some people are smarter and more organized than others. Maybe they have a better understanding of biology and physics and are able to do things like calorie counting and exercise planning more efficiently.
Some people are more obsessive and perfectionist than others. Maybe these people are able to completely abstain from booze and drugs, from staying up late, from cheating on their diet. These people are probably more likely to keep to their exercise schedule, not miss a session, and also are perhaps more likely to keep pushing their intensity to continue to see improvements.
To be successful at weight loss you have to score high in every component. You could be an independently wealthy, obsessive, intelligent person with nothing better to do than diet and exercise, but if your genetics suck, you'll probably always be fat. You could have great genetics but not have the time or personality that lets you stick to a strict and heavy regimin to see the results.
Bz is obese, he's been obese for years, he hasn't had much success, and he's headed for serious health problems if this doesn't change. Surgery is an extreme option but if his doctor feels he's a candidate, it's probably the right decision. At some point you need to just let go of the ideal fantasy (I can lose the weight on my own...) when it becomes a convenient excuse to not worry about it (...I'll start the diet tomorrow...) or even worse, permission to continue to be self destructive (...after I finish these beers and this large pizza).
Again, statistically speaking, the odds are incredibly small that anyone is able to lose weight (even a tiny amount like 20 lbs) and keep it off for over three years. I don't think anyone has even looked at 10 year statistics, since it's hard enough to even have anyone last three years.
Cyanista, Warnen, Morphix, what you guys have done is incredibly special and very rare. I've found that my own success was not repeatable by anyone I know in person, even when I am training them (the longest candidate lasted about two weeks before he fell off the wagon). It takes something special to be able to lose weight and keep it off without medication and surgery. Most people just could not do it no matter how much they want to.