I guess if I'm totally out of condition then exercising feels very inefficient. Once I'm in condition, though, it's calories in = calories and it isn't complicated, at least for endurance activites. If I pile on more activity then I need a corresponding amount of extra calories and it's simple arithmetic.

I only see that study cited by people who are looking for excuses to not exercise.

You're off the mark here - I'm in great shape and exercise more or less every day.

At the same time, I keep up with the latest science and understand the limitations of exercise as a means of sustainable weight loss for the general population.

Please stop talking about simple arithmetic - the body is not a simple machine and trying to conceptualize it as such is willfully ignorant.