I think you have hit on the problem. It is the parents' duty to form their children. If a child is unformed, one can't help but look to the parents (or other primary caregiver and the baptismal sponsors) as having primary fault in the matter.
As the Holy Father Pius XI wrote in Casti Connubii (on chaste wedlock):
"16. The blessing of offspring, however, is not completed by the mere begetting of them, but something else must be added, namely the proper education of the offspring. For the most wise God would have failed to make sufficient provision for children that had been born, and so for the whole human race, if He had not given to those to whom He had entrusted the power and right to beget them, the power also and the right to educate them. For no one can fail to see that children are incapable of providing wholly for themselves, even in matters pertaining to their natural life, and much less in those pertaining to the supernatural, but require for many years to be helped, instructed, and educated by others. Now it is certain that both by the law of nature and of God this right and duty of educating their offspring belongs in the first place to those who began the work of nature by giving them birth, and they are indeed forbidden to leave unfinished this work and so expose it to certain ruin. But in matrimony provision has been made in the best possible way for this education of children that is so necessary, for, since the parents are bound together by an indissoluble bond, the care and mutual help of each is always at hand.
"17. Since, however, We have spoken fully elsewhere on the Christian education of youth, let Us sum it all up by quoting once more the words of St. Augustine: 'As regards the offspring it is provided that they should be begotten lovingly and educated religiously,' -- and this is also expressed succinctly in the Code of Canon Law -- 'The primary end of marriage is the procreation and the education of children.'
"18. Nor must We omit to remark, in fine, that since the duty entrusted to parents for the good of their children is of such high dignity and of such great importance, every use of the faculty given by God for the procreation of new life is the right and the privilege of the married state alone, by the law of God and of nature, and must be confined absolutely within the sacred limits of that state.
"80. ... This sacredness of marriage which is intimately connected with religion and all that is holy, arises from the divine origin we have just mentioned, from its purpose which is the begetting and education of children for God, and the binding of man and wife to God through Christian love and mutual support; and finally it arises from the very nature of wedlock, whose institution is to be sought for in the farseeing Providence of God, whereby it is the means of transmitting life, thus making the parents the ministers, as it were, of the Divine Omnipotence. To this must be added that new element of dignity which comes from the sacrament, by which the Christian marriage is so ennobled and raised to such a level, that it appeared to the Apostle as a great sacrament, honorable in every way."