Very very few people sacrifice their own life for any kind of principle unless forced to. That's why those who do are often lionised!
But anyway, do you have a better first principle? If you don't care about staying alive why get out of bed at all, why not just starve to death? It's more work for sure.
Your fallacy is assuming that if the first principle is not protection of life, it must be its opposite, extreme disregard of life. There are potentially infinite choices of first principles.
Furthermore, you present no argument for your particular first principle beyond aesthetics (aka "I prefer this one"). You build on the implicit assumption that human life is valuable (and apparently more so than other forms of life) for which you don't provide justification. Well, you do argue that it keeps people alive. But again, that's a circular argument. "My value system is the best one because it fulfills the goals of my value system."
But anyway, do you have a better first principle? If you don't care about staying alive why get out of bed at all, why not just starve to death? It's more work for sure.