I could take the time to break down all his ignorance, but I will not.  I will say I am a distance cyclist, and once I got my salts right (you actually have to make sure you get enough salt so your blood pressure does not drop too far when you are keto) I had no problems with my 50m+ rides.  In fact many endurance athletes on KETO are breaking their PRs and even taking 1st place in ultras and other long races.

The simple fact is refined carbohydrates are bad, in general, for human beings.  One does not need to be KETO to improve their life but just cut out sugar and refined carbs completely.  All things in moderation.