As much as I love the I6 and the Falcon.... The V6 is favoured by Ford due to simple business economics. V6 engines allows for FWD layouts (which are lighter, cheaper to make and have less driveline friction). The Barra I6 would be too long to fit into most of the American Fords (or Mazda, Lincoln, etc). They also view the cast iron Barra engine as outdated and inefficient. And finally, most yanks don't give a sh*t about FWD/RWD, V6/I6.