I could've mention another conditions, like panic attacks or alcoholism (which isn't a personal choice, just like obesity in many cases, because you can unintentionally learn bad eating habits from a young age), but that's not the main point. And many stutterers don't work as hard on their speech and mental health as they could, just passively accept their condition (just like overweight people in my far from perfect example). Look at how many posts are about trying new things/methods to improve speech and how many are just pointless/depressing rants about stuttering.