Because you cannot be productive in that way on a smartphone alone. The smartphone is descended from simple communication devices, and adapted into a richer co

Because you cannot be productive in that way on a smartphone alone. The smartphone is descended from simple communication devices, and adapted into a richer communication environment and a content consumption device. You need a computer to do anything hacky with a smartphone, so you're more likely to get into the details on a computer in the first place. Smartphones are mostly useful for consumption of media, an activity that isn't really condusive to tinkering and modifying.