Motivation
There are a number of distinct reasons that people adhere to low carb diets.
Professional
This is my reason for trying these kinds of diets. As software engineers, we spend a large proportion of our time living sedentary lifestyles. We sit in the office or at home and zone in to our work for hours on end. This can be quite destructive to your health over time no doubt. Since we are not moving around so much, we are not burning energy so much and so the effects of carbohydrate rich diets are much more pronounced!
Medical
You may have been prescribed Keto if you have epilepsy or for a number of different conditions.
Experimentation
Just for fun.
Cosmetic
You want to lose weight.