Due to the overall spirit which dominated the council with it's overly optimistic attitude towards the world/men, the neglect to condemn many prevalent errors and the ambiguity of it's texts. The ambiguity emerges mostly from a combination of the verbose nature of the documents, the council issuing no canons and omitting plenty of distinct Catholic terminology in it's texts. However, that the council documents are ambiguous or that they did not condemn some particular error, is something which of itself doesn't makes the council texts erroneous. There is also the aftermath of the council, something which was poorly handled, to say the least.
The problem is not so much with them doing natural good but with the inversion of the end of The Church's mission, which by divine mandate is essentially supernatural and concerned with proclaiming the gospel, leading men towards faith in Christ and administering the Sacraments to them.
Those in the Church's hierarchy that I was referring to rather cast the Christian faith in a secular dimension and focus on the achievement of purely natural and temporal goods to the exclusion of supernatural ones. They are more concerned with issues related to politics, the environment, fighting poverty and hatred, eliminating war, etc. All of which is good in itself but not without any reference to the supernatural end of man and his necessity of repentance and conversion to the faith, which is what they omit and refuse to proclaim.
Ecumenism, which I mentioned as well, is related to this issue. The sort of Ecumenism which has become prominent is not one with the conversion of others to the faith as it's end, but with "getting along" with people of other religions, turning a blind eye to differences on matters of faith and focusing instead on keeping "peaceful" relationships and endless dialogue with them.
Thus the idea of proclaiming the gospel to them, of calling them to conversion, is altogether abandoned. As can be seen, for example, in
the message sent by the Pontifical Council of Interreligious Dialogue to Buddhists, on occasion of their Vesak festival. This document also highlights the problem I was referring to, namely, the focus on the achievement of purely natural goods to the exclusion of supernatural ones.
Evo