Here's an idea of what they should do for future adaptations: create a different Superman, while working within the established boundaries of the character (i.e is optimistic, compassionate and devoted to helping others). The Russo Brothers talk about this when discussing the climax of Winter Soldier and not taking Cap into an out of character zone.
http://www.vanityfair.com/hollywood/...tors-interview
Something that's also important to understand about Superman: The Movie, is that it is just that, a MOVIE adaptation which was influenced by roughly 30 years of established characterization, since Superman as we know him today, and the version that was adapted for that film, really came about some time in the early 1950s, with the Earth One/Silver Age continuity (the 1940s were really his development process into what we have now). In other words, long before the movie was ever even thought of.