Because not talking to users and then implementing a drastic change they don’t like sounds like a rookie move? Although, as I kind of allude to, I also place a lot of blame on management: Employees will make mistakes. Big ones. That’s life. A company needs to be structured so there are checks before those mistakes go out into the wild.
But, yes: Senior designers can also make mistakes. I’d argue they make less glaringly obvious mistakes, but humans will human.