I guess I'm one of those sad folks. I consider fitness to be a hobby because I enjoy it and set aside time several times a day to do it. I look forward to it. It fulfills me in a way.
I consider myself blessed because many people hate exercising - I enjoy it, and even crave it.
As far as why we're the fattest nation on earth - yes, there is a personal accountability factor at play, but the food industry is not all that great at offering people decent, healthful choices. For them, it's about how best to make a buck - and processed foods with cheap, harmful ingredients and a long shelf life are key to profitability. The food industry is also a powerful lobby for government - so if you wonder why schools don't offer better choices for kids, why harmful additives like HFCS are not regulated, why farmers are paid not to grow a bigger variety of crops, there's a big reason right there.