Most of them are older. All the Zelda games before Twilight Princess were rated E. The PS1 Crash Bandicoot and Spyro games were E, and they were awesome (note: only the PS1 games, when they were owned by their respective creators).
The problem is that video games, due to their interactive nature, are most easily done when combat is involved. A story must be told through gameplay that involves a clear win or loss: and the best way to tell a good story with engaging gameplay that can deliver a clear win or loss is when dealing with life or death. Thus, most E rated games are either really light on story or attempt to tell a good story and fail miserably in regards to gameplay.
We're on our way to figuring out ways to tell good stories with good gameplay and little violence, but as of now it's pretty difficult.