That's because keto isn't really a weight loss diet. It can be, but it was designed to reduce seizures in people with epilepsy. It's a healthy diet with the side effect of reducing weight if calories are reduced. It is popular as a way to lose weight because the fats keep you satiated for hours, reducing hunger and the feeling of needing to eat. Also, the reduction of carbs reduces the blood sugar spike and the subsequent sugar crash later that makes you feel hungry.

It isn't BS as I've lost a considerable amount of weight in a very short time on it, eating nothing but vegetables and meat. Usually eating (far) over 1,000 calories per meal, dripping tons of butter on literally everything, 3x a day, going from 223lbs to 180lbs in 3 months.

I know nearly a dozen people at work who've lost as much or more weight than me, eating like I did. In fact you're the first person I've ever heard of gaining weight on keto, on or off the internet.