Just came across this thread. When I picked up my new truck two weeks ago, I actually got out and looked if there was a protective film over it. It definitely sucks.

 

Alright, I know that we all know how reliable dealership information is... But I'll say it anyways.

For previous model years (like 09 with crystal clear screens) Ford used a much thinner lens for the backup camera. It apparently broke easily and was a source of problems. So for our trucks (not sure exactly when, but for sure 2011+) they started using a thicker polycarbonate lens that is much more durable.

Again, I can neither confirm or deny the truth behind this, but it did seem to be a reasonable sounding answer.