Each to their own. My body definitely strongly prefer very low-carb as my default, things like cauliflower should be banned… Good I don’t want it at all 
I never thought carbs or fat would be bad (is SAD low-fat? you can do that in the US? we eat very fatty here, that’s the tasty, that was always the norm…). Some people are surely thriving on 1000g carbs a day, good for them. They better don’t spend that on sugary cakes though even if they can pull it off for some time.
And there is a thing as being obsessed with health and specific details of one’s diet.
That is individual too. Some people needs or enjoys the details and experiments galore. Others would go crazy without sweets. Eat sweets them though preferably healthy ones. Healthy is individual too. I never ever believed any edible, proper food would be bad for me. My body handles even sugars well - just in tiny amounts (and surrounded with lots of fatty protein especially afterwards).I can live with that.
And I think it’s very much known that very high activity level requires more carbs. I probably never will be that active but some people are. I do my tiny little lifting (well it’s serious enough to ME) and the less carbs I eat, the better.