Why we labour nutritional quality amongst a world going crazy for a ‘deficit’

The elusive caloric deficit to burn fat or lose weight is touted by many diet styles to promote wellness and health when in actual fact: and this is my own opinion: for many that comes at a much higher price.
Long-term metabolic dysfunction, downregulation of metabolic (life!) processes and a constant state of fragility, anger, irritability and yo-yo coping strategies are therefore prevalent.
We are in a society where an 800-calorie diet is more approachable than starting at a 2000 calorie DRV. Even though it has been recommended by the UK government for many years, the 2500 and 2000 calorie model for an exercising population would infact induce fat loss results in many desire especially if their macronutrient balance and exercise intensity is met. I can argue for many athletes this would be potential starvation.