What does it matter who ultimately manufactures the product?
Part of a companies value is based on how much property they own. Also known as assets.
If apple sold off all of their property, would that money equal what the company is valued at?
Since apple only owns some office space, maybe some land that the building is sitting on, some servers,,,, the company does not have very much physical value.
Now take exxon - they own chemical plants, drilling rigs,,,, physical property that has a real value to it. The people at exxon can point to an offshore drilling rig and say "that rig is valued at 10 million dollars".
By not owning the manufacturing plants, apples "real" value is decreased.
It appears to me that apples stock prices are inflated by how well their products sell, and not by how much money the company is really worth.