I definitely think people are afraid or embarrassed to acknowledge that there may be physical, biological causes for obesity. We're all here at 3FC because we're committed to doing something about our excess weight. Since (at this time) science and medicine have very little to offer us to assist in our lifelong struggle, we all realize that it boils down to personal responsibility for weight management. And no one here wants to be perceived as making excuses and not stepping up to take personal responsibility.
You're right, Susan, people here do get "pretty wound up" about blaming weight on outside causes and posters are gun-shy about saying something that in the least bit implies that they're not totally, 100% responsible for their weight problems. As a matter of fact, most people go to great lengths to call themselves names and beat themselves up for being overweight.
I think both a belief in genetic/biochemical causes for obesity and a sense of personal responsibility for weight management can co-exist in harmony. One deals with causation; the other deals with how we fix the problem. I hope we all recognize that it's overly simplistic to say "I'm fat because I eat too much." The larger question is: why? Why do we want to eat more? Why do our bodies return to a setpoint? What makes us hungry? What shuts down appetite? And science has much to offer in answering those key questions.
I'm not at all ashamed to say that I believe that I was born with a tendency for obesity. Obviously I've taken responsibility for dealing with it, but I truly believe it's not a fair game we're playing. The genetic deck is stacked against some of us and it undoubtedly makes weight management much, much harder for some of us than others. Seriously, does anyone still think that it's a level playing field when it comes to weight?