"Y chromosomes with defective male-specific genes, especially those involved in sperm production, are unlikely to reproduce and pass on those genes to their sons, which knocks highly defective chromosomes out of the gene pool. Genetic changes that do not favor reproduction are likely to get weeded out of the system."
So I am wrong.
Men with defective Y's have problems fathering children of both sexes. Their daughters are normal, but their sons will inherit their father's fertility problems. Mutated badly enough and the man is sterile and they can't father children of either sex, due to low sperm production.