Have you tried to re-engineer the wheel?That's not entirely correct ( although as an engineer, I totally agree)
I don't design cars but do design other stuff and the restrictions are the same.
More often than not the DFMEA requirements will include cost/space and material requirements which severely limit design considerations. Everybody wants the most compact design that a robot can do.
I have personally put maintenance friendly things in machines and been instructed to remove them because of additional manufacturing time or costs or because it throws something else out of limit.
That's not the case every time obviously but its almost SOP in the mechanical design world.