Just like every person dies, so does every society (no matter where you draw the lines around it). We can't justify what we do solely based on survival. What's worth doing has to be worth doing for its own sake, here and now. That we are around to do things in the future, doesn't matter if nothing is worth doing.

Put in a catchier way, if nothing is worth dying for, then nothing is worth living for either.

I think you'll find this is a very old viewpoint. As is the smear that we reject any care or duty for society. "This may seem harsh and stubborn and unconciliatory; but it is to treat with the utmost kindness and consideration the only spirit that can appreciate or deserves it."