Upon hearing of Motorola’s Project Ara, its easy to lapse into thinking about all the reasons why itll be hard — almost impossible — to pull off: customers wont have incentive to buy new phones, modules will be too expensive; the list goes on. And if you can think of 30 reasons not to build such a thing, Motorola’s designers and engineers can probably come up with 300. But against all odds, theyre doing it.