Childhood motivation can be quite powerful.
"But in a head-scratching example of deus ex machina, Superman realizes he can save Lois by going back in time (by, get this, reversing the spin of the earth)." So says Kevin Polowy today in Yahoo! movies. And I say NOOOO!! Did you not watch/understand the movie, Kevin? Supes did NOT reverse the spin of the Earth, he flew around the Earth at the speed of light and WENT BACKWARD IN TIME! What would you expect to see if you're going backwards in time? You'd see the Earth slow down as time crawls to zero speed (as it did) and then reverse spin as you were going backward through time.
I'm happy to hear arguments that breaking the light barrier wouldn't reverse time but, assuming it does, what was shown was perfectly clear.