Hmm. I wonder if the same people who are most blatantly disregarding the doctor's recommendation to exercise are ones who also disregarded "health" advice in general and that's what led to them being diabetics (or at least such severe diabetics) in the first place... ?
OBVIOUSLY NOT TRUE FOR ALL
My grandfather was a diabetic and if the doctor said do it, he did it. He got off insulin and controlled it through a strict diet. He also exercised every day. He didn't cheat at ALL. He soaked his feet in a vinegar bath every night, wore special socks, etc... and he lived 20+ years that way, and when he died it was because of a hospital infection when he had knee replacement surgery, not anything directly related to being diabetic.
I know someone my age who is a diabetic and he doesn't exercise at all! And he eats stuff like full Sugar desserts all the time...