As I said, it is doable but takes more effort and time. Yes, if one partner stays at home they can spend more time preparing meal than if both work long hours.
I'm sorry dude, but this just isn't true.
Provided you live in a warm enough climate, and are from a culture where protein-rich legumes like beans, lentils, or chickpeas were a normal part of cultivation, it is just as easy to subsist on on vegetarian diet as a mixed one. Indeed, given most traditional diets developed over time, they've pretty much "evolved" to offer full nutrition. So there is a fairly complete agricultural package in the Middle East, Mediterranean, India, East Asia, Mesoamerica, etc - which allows for a healthy Vegetarian diet.
On the other hand, a totally meat-based diet is near impossible without really catholic tastes. The Inuit come close to doing it, but largely because they ate a lot of fat like blubber, which counteracted possible protein poisoning, along with eating things like fish oil, liver, brains, and whale skin (all raw) which allowed them to get vitamins A, C, and E which are generally lacking in cooked mammal muscle tissue. Even in their case, they eat seaweed and forage wild plants in the summer, which help somewhat.
I can also say, having been a vegan for 15 years now, and a vegetarian for 19, from personal experience that although I generally eat what I want, and rarely take supplements, every time I get bloodwork done all the vitamins and minerals are where they should be. Really, besides B-12, zinc, calcium, D (in high latitudes only), and iron (for women only, as you typically only lose iron when you bleed), a vegetarian diet is naturally complete . And in traditional diets, most of that was taken care of, as trace minerals used to be gained because they didn't wash produce very well, or because people got enough B-12 from bacteria on the food.
Finally, I don't think people realize how bland a meat-only diet would be. Taking it to its logical conclusion, you wouldn't be able to use any herbs or spices widely used in modern cuisine, except for salt. Maybe a whole different set of seasonings would have to come into being, made of things like say crushed beetles, but this would necessitate the development of a significant "carnian" subculture which would experiment and appropriate.
Edit: My basic point is that a totally meat-based diet would ultimately require even more planning to work, in the modern world, than modern vegetarian diets do. And unlike vegetarianism, I think it would be practically impossible for someone in the pre-modern era, who didn't understand nutrition, to survive on it if they didn't come from a heavily carnivorous culture which ate a lot of "offal" already.