(((((Linz))))) I think there is judgment and then there is JUDGMENT.
When I remind people, as I'm wont to do, that they are judging people in direct contradiction to the gospel they claim to adhere to (Mat 7:1, e.g.), they often come back with something like "we make judgments every day. How can we not?"
But you're right: having opinions,esp. when a person's actions threaten to harm you, or infringe on your rights, is not only natural, it's necessary.
If a person says, "The Bible says to love each other and not to judge, so, those people who are hating and judging and sneering, even though they call themselves Christians, don't seem to be very Christian," that's an "I" statement that is a more of a fact-based opinion about what I perceive.
But when a person says "Because you don't use the same religious terminology as I do, or because you eat meat on Fridays, or because you sprinkle instead of dunk, you aren't SAVED and God will send you to hell," that's a judgment. It's a 'you-statement' opinion that is presumptuous and arrogant. This is the kind of judgment that Jesus talked about in Mat 7:1 etc.
Of course you always have the odd zealot who believes that just to disagree with him is a treacherous act of demoralizing judgment. They tend to be the ones who have no concept that their personal opinions might not be pure, unadulterated fact. In my experience, these tend to be the "blind-faithers" and since they are told not to think about their beliefs, they have no recourse to debate an honest opinion except to complain that you are judging them by disagreeing.
Sorry this is so long. Seems like I can't say anything in less than 2500 words. No, I'm NOT long-winded... I prefer to think of it as *colloquial.* :)