they got away with it at launch because the limits applicable to the weight and balance envelope contained substantial buffers to accommodate that system rather than an index effect for each kg in each seat based on passenger weight. Please learn something about weight and balance before making such a statement.
Each kg in each seat
Wrong again.
I believe their system works on 3 aircraft zones and not on the individual seat. So a person can be anywhere in a particular zone (front or back) yet have no effect on the weight and balance calculations.
Please get your facts right before making false statements. Seems obvious here who doesn't know about weight and balance.