Yzj, I will strengthen your post. The Rema (YD 340:5) says in the name of the Or Zarua:
הפורשים מדרכי צבור אע”פ שאין מתאבלין עליהם מתאבלין על בניהם
Kedoshei Pittsburgh were probably several generations removed from the Jews who went OTD. Even in their case, they were caught between the rock of Czarist Russia and the hard place of sweatshop bosses who posted signs “If you don’t come in on Sat don’t come in on Mon”.