Part of the problem, as I've understood it, is that the crew and cast of the film didn't know how to end the movie either and thus, it gave off the impression that the Bruce Willis character would be forever stuck in his fate, in this endless, hopeless loop. Perhaps this is because the people who wrote the script had a cynical streak to them, or maybe it's because the film was meant to seem open-ended.

Good question.

Take care all.