So what you're saying is that instead of 1v7, you want 1v1v1v1v1v1v1v1?
That's exactly what the game already is, and that's been the goal since the beginning--"In Camp Crystal Lake, it only matters if you survive." That being said, I'm sure the devs have no plans to encourage players to work together.
I'm glad they decided not to reward altruism, because when there's no incentive to helping other players, it all comes down to practicality and morality. You either work together because it'll help you escape faster and maybe because you're playing with your friends and you actually want to escape together. Or if you have no friends to play with and/or you just want to go it alone, there's nothing to stop you from doing that.
If there was a reward system for helping others escape, then it would ruin the point of working alone. Players would feel pressured into working with others, even if they don't want to. I mean, if you could get more points by helping people, then why wouldn't you do it? It shouldn't be that way. One playstyle shouldn't be more desirable than another just because it equals a better score. You should feel comfortable playing however you want.
Also, personally, I disagree with the stance that if you're willing to leave your teammate in a video game to die that it translates to "you'd be willing to leave your close friends and family to die in real life." Those are two totally different, incomparable situations.