I can see why people do this diet. Something that a ton of people say while they're carnivore is the lack of bloating, which some people have had for a long time. You really can't blame someone for looking for relief, especially from digestive issues. I myself have been thinking about doing it for a while, but I'm afraid that I'll end hurting myself in the long run, due to less CO2, less thyroid hormone, more ammonia due to gluconeogenesis( and ammonia needs CO2 to turn into urea). I guess that's all that I'm worried about when it comes to a carnivore diet. Otherwise, it seems awesome. Stefansson did this diet for a long time and, as
@Wichway? said, he remained healthy, and there are people who have eaten like this for years and are fine. Groups of people like the Inuit have eaten like this for generations too, although there is the confounding factor of big amounts of omega-3 consumption, which may account for some bad things they were suffering from, such as looking older than they really are. The Mongolians also eat basically meat, meat fat and milk, right? Not zero carb, but not high carb either. They seem healthy, although I'm open to evidence of the contrary.
I'm probably gonna try it one day, honestly, to see how I feel on it.