As humans, we have ideologies and they mostly interfere with our thoughts.

When we meet someone for the first time, it's almost impossible not to have a perception. We always have a bias, a thought of what the person constitutes.

Sometimes, it's wrong but at other times with our predetermined instinct it's right. Being judgemental can be wrong mostly if jealousy is allowed to creep in or our perspective is negative.

My conclusion, being judgemental may be wrong when done with a negative thoughts but if we are open and without prejudice our instinctive judgement are mostly right.