"Argument from fallacy; if your intake was reasonable, you would not need to lose weight."
Of course not. The point is to return to a normal calorie consumption ( for you) that keeps your weight neutral - this isn't dieting it's just returning to normal. At this point you can diet, exercise or both .All will work, the exercise will be hard but you'll be fit and not suffer hunger, & retain/increase muscle.
If you chose diet then you'll be hungry and lose muscle and have lower basal metabolic rate
"Extra exercise accounts for such a small amount of your calorific expenditure" - depends how much you do - when I was losing 35kg I would usually do 800-1800 Cals a day. You can lose 1kg a week or more doing that. It's a lot day-in day-out but it worked (for me)