However, if everyone was a perfect nihilist, you wouldn't have cheap old cars to drive because nobody would have made cars. You wouldn't have a cell phone, and especially a data connection, if not for the space program. And so on.
So while I don't think it's a problem if some people take your viewpoint, I think it's a problem when everyone does. Somebody has to care enough about the environment to stop rampant capitalism from destroying it so that we have a planet to live on 50 years from now (electric cars, improved public transit.) Someone has to care enough to get humans off the planet so that when it is inevitably destroyed (asteroid, nuclear war, virus, overpopulation) the human race can continue elsewhere.