I don't think this is even the case. I think Apple is concerned with the user's experience. They don't want some random 3rd party component affecting the perfor

I don't think this is even the case. I think Apple is concerned with the user's experience. They don't want some random 3rd party component affecting the performance or functionality of the device, or some 3rd party's poor-repair job. Because if the repair job is crappy, and it only shows up down the road, the user blames Apple. Apple wants its users to connect positively with its products. This is why when you take your laptop into the store, they don't offer to just desolder the bad chip, and replace it. They don't want to take the time or money to train their store in doing these repairs. There's a lot that can go wrong and its easier to just make the policy to swap the entire component - the whole logic board. It's a lot quicker to do, it's a lot quicker to train, it's a lot lower risk in terms of chemical exposure, proper-ventilation, and materials disposal. If they take the entire bad motherboard, they can box them all up and ship them in bulk.