My thoughts? When Dr. Atkins wrote his first book back in the 70's, he had only been using it on his patients for a few years. 30 years (and thousands of patients) later, I think the good doctor learned a few things about what works and what doesn't work as well as better ways to apply the low carb approach to make it more of a "Way of life" instead of just another diet. Perhaps he didn't address or focus on exercise in his earlier books because it was a given at that point that you needed to exercise or because his focus at that point was on getting out the "too many carbs are not good and fat is not evil" message. Dr. Atkins isn't the first person to start out with a good idea and then improve on it as they applied it and learned more.
Ask any doctor that treats overweight patients and they will likely tell you that one of the largest obstacles in weight loss is compliance with the diet or menu; if patient's can't or won't stick with it, it does them no good to tell them they need to do it.
As someone already mentioned the "effective carb" principle applies to more than just glycerin and sugar alcohols found in low carb foods and candies, it also applies to the amount of fiber found in natural foods such as berries and vegetables. Since we cannot digest the fiber found in these foods (only ruminents can), there is no real reason to count them and restrict your amounts and choices in that way. More variety, greater quantity = more satisfied (and therefore more compliant) patients. Besides...being allowed to eat a few more veggies isn't likely to slow too many people down. How many of us got to where we are by eating too much lettuce or broccoli? Low carb bars and candies, OTOH, are another matter. I personally feel that using half your daily carb allowance on what basically amounts to low carb junk food isn't exactly what Dr. Atkins had in mind. Used as an occasional treat or in a situation where there are no other good low carb choices available? Absolutely! Eating them every day or sometimes even several times a day instead of veggies, nuts or fruit? Not a good idea, IMHO.