I think that's a fair point - especially if one prescribes to most economically efficient == most moral - which not all subscribe to (although perhaps of all people Musk would subscribe to this theory).

That said I could for see cases where the laptop class could be isolated from pain when a separate class has to do the physical work. Imagine a scenario where the laptop class engineer does some sloppy work in order to pick up the kids for soccer. The goof up requires 100 production line people to redo step 8 of 30 steps for 3 additional hours.

That goof up will be less visible there than at a company that has outsourced production line work. At the outsourced production company the goof up will show up as the additional change order which will have a directly mappable line item on the quarterly accounting that the responsible engineer will need to answer for.