The purpose of the validation step is to get someone out of a reactive, unreasonable frame of mind into a frame of mind where you can start problem-solving together. It can feel condescending if they're already in a problem-solving frame of mind. "There, there, it's natural to be hysterical."

It's like when your team is sitting together handling an issue calmly and competently, and a manager strides into the room yelling, "Okay everybody, calm down! Everything's going to be okay. No need to panic." It shows that they aren't paying attention and don't appreciate the professionalism of the team.

Or the classic example of,

"Hey man calm down!"

"I am calm!"

One of the best ways to upset someone is to claim they are upset.