I've been VLC/carnivore for about a month. Why? Mainly because I've been LC for many years now. I've tried different plans. I believe in having an arsenal of plans and strategies, not just hugging one person's philosophy. (ETA: I DO believe that newbies are best off picking one plan and sticking to it for a long time before shuffling it up.) My diet changes with the seasons and with financial ups and downs.
Through all of those experiments, I've felt the best at or near ketosis. Most recently, I think I can credit ditching gluten as a major factor, but higher-carb paleo does me no favours. With VLC, I absolutely LOVE the food that I do eat, and at the same time I achieve that blissful disinterest in food - resisting temptation doesn't exist because the temptation doesn't exist. My threshold for waking up the addiction monster is pretty low.
I don't give a rat's behind about what Kitavans or Inuit ate. They didn't trash their gut with high-fructose corn syrup and gluten like I did for the first 25 years of my life, so all bets are off. For the same reason, I don't trust an unsupplemented meat and water diet to have sufficient nutrients for people like me with dubious absorption. It's all a big experiment. That's fine, but I won't be arguing that it's superior.
Another reason I decided to go almost ZC is that I appear to have the early signs of arthritis. I'm concerned about the possible connection between the nightshade veggies and inflammation. Well, jeez, those are my favorites.
So I've been sticking with "condiment" veggies: onions and celery for cooking, whatever trace veggies are in my curry paste, etc. (Yes, I know there are peppers in it...)
An additional reason: I have no food scale anymore. VLC makes it easy to eat good meals, eat according to appetite, and not worry about the numbers.