BIOLOGY 1010 - Sickle-cell anemia is caused

Sickle-cell anemia is caused by a single point mutation in the hemoglobin of human red blood cells. It is a recessive gene. People who have sickle cell anemia are homozygous recessive and suffer terribly from this disorder. Now I have stated in lecture that mutations are neither good nor bad. Rather it depends on how the mutation effects the survival of the species. If the mutation harms the survival of the species it is bad, if it helps the survival of the species it is good. Now tell me is this mutation good or bad? What do you think?