Perhaps it would be helpful to differentiate between the halachic definition of tinok shenishbah, which, apparently, Reb Moshe held is virtually non-existent in the US, and the case of Jews being raised/educated badly and thus thinking that there is nothing wrong with what they are doing despite them knowing that the Torah considers it wrong.
The people in Pittsburgh Hy”d may not necessarily technically have been tinokos shenishbu but they may be cases of “omer muttar” and deserving of our pity that they didn’t know any better.