Direct answer to OP:
Because the iPad doesn't include the hardware to handle voice cellular calls. Nor does the iPad include hardware in the iPhone to manage the user experience, e.g. sensor(s) used to detect when phone is held to the ear.
Deeper answer:
Apple doesn't see the use case as being worthwhile to support. Likely due to many reasons mentioned in this thread, including:
Even deeper answer: Cellular phone service typically requires a service contract. iPad cellular data service has historically treated data access as equally a pay as you need or as a service contract approach. I suspect that users lean more to pay as you need month to month more frequently than selecting a contracted service for data use.
Personally, my interpretation that Apple thinks of the iPad as a non-contracted device is probably a big factor in the design choice. Probably just as important as the form factor problem.
Because the iPad doesn't include the hardware to handle voice cellular calls. Nor does the iPad include hardware in the iPhone to manage the user experience, e.g. sensor(s) used to detect when phone is held to the ear.
Deeper answer:
Apple doesn't see the use case as being worthwhile to support. Likely due to many reasons mentioned in this thread, including:
- device form-factor is too large to be comfortable
- cannibalizing sales
- Facetime, iMessage, Skype software solutions can provide this functionality to users who care.
Even deeper answer: Cellular phone service typically requires a service contract. iPad cellular data service has historically treated data access as equally a pay as you need or as a service contract approach. I suspect that users lean more to pay as you need month to month more frequently than selecting a contracted service for data use.
Personally, my interpretation that Apple thinks of the iPad as a non-contracted device is probably a big factor in the design choice. Probably just as important as the form factor problem.