Let's talk about judging for a moment.
I think one of the most misused passages/phrases from the bible is "Judge not, lest ye be judged" or some paraphrase from it.
In context:
Do not judge, or you too will be judged. 2 For in the same way you judge others, you will be judged, and with the measure you use, it will be measured to you. 3 Why do you look at the speck of sawdust in your brothers eye and pay no attention to the plank in your own eye? 4 How can you say to your brother, Let me take the speck out of your eye, when all the time there is a plank in your own eye? 5 You hypocrite, first take the plank out of your own eye, and then you will see clearly to remove the speck from your brothers eye.
6 Do not give dogs what is sacred; do not throw your pearls to pigs. If you do, they may trample them under their feet, and turn and tear you to pieces.
The idea that we aren't supposed to judge others is part of this whole secular world thinking. Yes, we can judge, but we better make sure our house is in order before we do so.
We can certainly judge a person by their outward actions, which is why we can (and should) judge the actions of the people in this church. We can do this because the bible actually instructs us to do so!
2 Timothy 3:16
All Scripture is God-breathed and is
useful for teaching, rebuking, correcting and training in righteousness...
and
Matthew 18:15-17
Dealing With Sin in the Church15 If your brother or sister[
a] sins,[
b] go and point out their fault, just between the two of you. If they listen to you, you have won them over. 16 But if they will not listen, take one or two others along, so that every matter may be established by the testimony of two or three witnesses.[
c] 17 If they still refuse to listen, tell it to the church; and if they refuse to listen even to the church, treat them as you would a pagan or a tax collector.
The members of the church who were upset that their pastor's son was going to marry a woman with a history weren't doing what the bible instructed them, right from the start. On top of that, there was no sin in what the pastor's son and the woman were doing.
But the people judging the people in the church are doing so rightfully, as commanded in scripture.
The short form of this is that yes, you can have bad judging and good judging. The people in the congregation were partaking in bad judging. Those calling them people in the congregation out are doing it as a call to repentance.