Among LH's Airbus fleet only the A321 has proper exit seats. Exit seats on the A320 have slightly more leg room but you cannot get out of the window seat without disturbing passengers in the aisle and middle seats. The A319 doesn't have any seats with 'more legroom' as LH call them.

Elites flying on Economy Light fare do not get free ASR. And some people don't like exit seats.

On a longhaul flight on the A380 before new Business seats were installed, I was in 27A on the upper deck, an exit row with almost unlimited legroom (similar to what row 83 on the upper deck of 744 used to be and great for the 'seat trick' ). No one in the seat next to me (it was blocked) and 27HK remained unoccupied.