Do you agree that most people misuse the phrase "judge not lest you be judged"?

I can see where that phrase can be used when someone is trying to belittle someone and build themselves up by pointing out their sin, but what about when someone is genuinely concerned about whether they are truly walking with God or not, particularly when they themselves call themselves a Christian, or even worse, witnessing to other people and preaching the Gospel without even having witnessed the Holy Spirit themselves? Would it not be the right thing to point out that sin to make it clear to them that they need to repent. Shouldn't we be concerned that those who preach the Gospel are true witnesses of Christ? Wouldn't it be my business then? The Bible says to examine oneself daily to see if you are in the faith, so wouldn't be a good idea to tell someone they ought to examine themselves? Also, even if I have a log in my own eye, I would certainly want to know about it, and that gives me more reason to judge!