Wolfish: Yes, it appears the Chofetz Chaim is saying the children born from unions in which taharas hamishpacha were not observed will be wicked, but 1) we don’t know if we understand his words — perhaps he did not mean always, 2) he may well have been exaggerating for emphasis, to underscore the importance of this mitzvah?
If this were literally true that the Ba’al Teshuvah movement would be a contradiction in terms — since they’re all inherently wicked because of the circumstances of their conception what’s the point of them trying? We have to rely on the authority of the greatest tzaddikim and Torah leaders of our time, and they are all 100% in favor of people becoming BTs.
You can’t use your own personal interpretation in one line of the Chofetz Chaim’s voluminous works to cast away the unanimous authority of all rabbis of the last generation or two that all Jews should become Orthodox and engage in Torah and mitzvos to the best of their ability.