The mentally retarded daughter was withdrawn from marriage only because she hid other medical conditions, and her mother-in-law said it would be better to raise a pig, what do you think?

If the marriage was withdrawn because of concealing other medical conditions, then I think the man did the right thing. People value honesty, and although the daughter has an IQ problem, that's not why the man withdrew from the marriage. It's still the other problems that the woman is hiding. Although the mother-in-law's argument is not agreeable, but the approach is still right.