I think people like to sit near the front- just as people prefer to sit on the upper deck- there may not necessarily be a great logic for it however if that is what people want then good LH is attempting to follow their requests?

I have a colleague who swears by saving time sitting at the front of the aircraft- even when as you have mentioned that on many aircraft sitting closer to the door of exit is far faster (i.e. row 14/15 or 24/25 on a LH 744 in business are usually the fastest business seats to exit from).