For me it's about finding the right balance for my body. (I follow WW, btw)
Low-fat did used to be the big thing. Now it seems to have shifted to Low-carb. Who knows what we'll be seeing in the future?
Fat in food does not necessarily make you fat. It's calories in/out as you've said. Yet, stripping off fat used to be the easiest way of eating fewer calories in general. However, it doesn't mean fat is the "enemy" or anything.
Finding the right balance for your body is the goal. Eating enough fat, carbs and protein for your body to function properly. For you to be satisfied.
There are plenty of healthy ways to eat lower carb now-a-days, and you might find something that works for your body.