no Built-in Cellular Modem in MBPs,tell when???

Many devices with cellular modems are sold at a subsidized price with a contract for cellular service. Apple chose not to do this at this time. Their reasons for this decision are not clear but it might have to do with the terms of the contract that they would be offering with a carrier. Selling the device without a carrier would not be a complete solution and so doesn't fit with Apple's typical product offerings. The price would also be much higher without a contract.

It appears that Apple is instead pushing a tethering solution instead. Users who tether are connecting their computers to their cell phones by cables or wifi or bluetooth.

Selling a computer like iphone and selling a computer like macbook is not that different. It's all in the mind. If you want to have 4G in a computer then you put it in. It's that simple. No excuses needed. Apple doesn't want 4G and is probably stalled by the American phone companies yet again. They are the one that don't want data traffic in their carrier networks. The rest of the world has left America in the dust when it comes to mobile computing. It is what it is.