So the logic is it is better for a man to unknowingly raise another man's child and stay married to his cheating wife than for the man to find out his wife cheated on him and divorce her?
Home DNA testing is also illegal in France, so they definitely seem to think that ignorance is bliss.
Reminds me of the way nuclear explosions contaminated all steel with radioactive fallout. For applications that require the lowest possible radiation levels they have to use steel created before the first nuclear bomb was detonated.