The Ketogenic diet is actually fully effective in many patients. Interestingly, its more commonly used as a "last resort" when patients don't respond to pharmaceutical interventions instead of a first line of treatment.
The people who have been mostly managing their conditions via diet without understanding whats happening. Basically they eat healthy, and it mostly works.
People who love food / don't want to cook healthy and refuse to acknowledge the possibility that's causing problems.
People who say they eat healthy but really don't. (Salad once a week)
Or a variation, people who ate a salad, didn't get better and claim diets don't work).
The ones who are at deaths door and are finally desperate enough to try anything.
Actually following a strict diet like KETO / AIP. Paying close attention to trigger foods, etc. These ones often can reduce or eliminate medication.
Learning to be honest with yourself about food is one of the major challenges. Giving up various food addictions can be brutal.
I agree that on the surface, it sounds dreadful. The problem is that many doctors have found through experience that patient compliance with a daily pill is much better than with dietary changes. If a doctor wants to actually help a patient, the treatment that a patient will actually do becomes the most effective by default.
Having said that, I do think that doctors need to be aware of and make sure the alternatives are discussed with the patient. The paternal MD attitude of just tell the patient what they think the patient needs to hear should not be tolerated. If I ever get that vibe from a doc I move on and find someone who will respect me as a patient.
I think that happens because that is what most patients want. They don't want to give up pizza and alcohol. Give me a magic pill instead so I can do what I want.
Keto worked for me only when I cut out carbs completely, I eventually switched to zero carb because it's easier to maintain.
As long as I allowed myself anything carb, I'd got on a binge-frenzy, even with dairy... willpower is a terrible thing.
It's a last resort because adults can't reliably stick to the diet and doctors know it. People don't even stick to medication very well. It's really only prescribed in kids with severe forms of genetic epilepsy because it works well for those conditions, and their parents control what they eat. It's a lot easier to take a pill than to change your entire lifestyle.
Unfortunately, keto doesn't always control seizures either. Pills still work better than diet for some people.