You see this in aviation and heavy rail transport as well for a similar reason. The critical items like the engines, control systems and emergency equipment being expensive is obvious, they've been heavily tested and made super resilient with very strict certification criteria, but it even extends down to things that has pretty much zero impact on safety. That flimsy seat back table that can barely hold your laptop and that hard as a rock cushion cost the airline far more than you can imagine, costs which are inevetably passed onto you.