An answer and some comments. Strict liability under the MC means that you don't have to prove negligence on the part of the airline to win an award. All that matters is that the loss of life occurred.
But before we claim this is unjustified ambulance-chasing, we need to know a few facts. First, is Lufthansa trying to get by strictly via the MC liability of less than USD 150,000? Given the ease of showing that the monetary damages from the loss of a family bread-winner in a wealthy western country are often easily in the millions, 150,000 is a pittance. I would guess that any reader who had lost a loved one on that plane would not think that this is close to enough compensation.
But another unknown is whether Lufthansa is offering full compensation for loss of earnings, etc., and this argument is strictly over an additional award for pain and suffering. Until all of these facts are known, we should not be quick to pre-judge who is right and who is wrong in this matter.