Can somebody please explain why BMW climate control isn't climate control?

Or am I doing something wrong?

I want 23°C so I set it but if it's cold I get no heat unless I mess with the heater dial in the centre air vent and turn it from blue setting to at least 1 red?

What is the purpose of this? Why is this even a thing? Why does every other manufacturer allow a simple change of temp to get results while BMW needs you to phaff about with a heater dial in the centre vent?

Bloody confusing for anyone borrowing my car.

Cheers!