Reply To: Should Some People Be Considered "Unmarriable"?

Reb Moshe Feinstein was opposed to Dor Yesharim, he felt that one who broke off a shiduch based on a possibility of passing on a genetic disease was lacking in his faith in Hashem. He reluctantly acquiesced exclusively for Tay Sachs that has a 100% mortality rate and only before the shidduch progressed