People who only eat Paleo foods....can usually do whatever and will probably lose weight (or at least not gain more)
People who eat breads/cereals and other crap need more control (aka Zone %s and stuff like that)
Hormones and weight loss go hand in hand....low carb is just an easy way to let the general public not "improvise" and eat too many wrong carbs that just elevate insulin. Also for those that have more stubborn fat/insulin resistance factors and do not exercise with high intensity, a low carb approach may be a better strategy...again a hormonal thing. There doesn't have to be one right way....there never is.