Why the low rating?

Because:

1) It's a mediocre movie with an obvious message about 20/20 hindsight and how if we knew then what we know now, we wouldn't have made the mistakes we made.

2) Nicolas Cage is not the best part of the movie at all; in fact, he is the main reason it sucks. He's too young, horribly miscast anyway and puts on one of the most obnoxious voices ever in the history of filmdom.

3) Sofia Copolla is also terrible in this. (She literally looks and sounds mentally challenged.)

4) Kathleen Turner looks stupid trying to look and act like a 1950s teenager. Someone like Audrey Hepburn, who still looked young as she was pushing 40 could've pulled it off. Turner not only looked her age but had a deeper, sultry voice that made her sound even older.

5) It's an obvious lame attempt to cash in on the Back to the Future franchise, which was at its peak.