People thought the bubonic plague and cholera were God's will up until the germ theory of disease was discovered, happy to pray and cast spells while wallowing in their own feces in flea-bitten squalor, and that's not much different (or much more rational) than arguing that epidemics should be accepted because they're "evolution's will." Believing that nature has a plan only causes unnecessary suffering. Nature no more has a plan than does the dust in a dust storm.
Evolution doesn't care for happiness, strength, health or anything like that.
It only optimizes the number of copies of genes in given circumstances.