Why do time-travel stories often have the characters “returning” to the future?
The possibility of time travel normally creates paradoxes. If you can travel into the past and kill your grandfather, how did you exist in the first place?
The usual way of dealing with the paradoxes of time travel in SciFi movies, books or TV series is to invent arbitrary rules (I think this is the Dr Who solution), move so quickly that the audience doesn't have time to think too much (Looper is a good example of this) or to just ignore the problem (Terminator 2).
Terminator 2 is typical of many treatments. The paradox is that the future that is avoided has already influenced the present: so how can the present not be self-referentially altered as a result of avoiding the future...
I don't think these problems detract from the great stories involving time travel. But, SciFi is a creative medium and I wondered whether versions or rules for time travel have been invented which do not suffer from the normal paradoxes?