People who don’t make money, have to take care of childcare while working 2-3 jobs, probably aren’t able to cook themselves. Nor are the people who live in food deserts that only have limited options able to optimize around a specific diet that’s not restricted by availability.

I cook my own food and optimize around eating healthy. I wouldn’t be able to do it if I made less money or had a more demanding job or didn’t have great grocery stores in a 10 mile radius or had to spend time in childcare or any of the other completely valid reasons people have.

Besides, you yourself just described “do things in moderation” yourself: holidays, Christmas, restaurants etc. That’s really what the philosophy is.