Because no one really cares. We will live on this planet until it is possible and until we adopt life on another one.. however it could be be changed
Judging by the fact that Ilon Mask is actively trying to start moving to Mars, I think things are very bad on our planet. We probably do not even fully suspect the scale. I hope that it is not too late to change and projects such as Greencoin will be able to fix everything!