A closed, iron gate gives off a very distinct impression: You are not allowed nor welcome here. This place is restricted and only a select few have access.
When you are in a leadership position, there is a spectrum of openness you can impress upon your team. Everything from an iron clad gate to an open, welcoming door. The first creates a clear distinction between master and worker. The second can develop trust and clarity.
If you are unapproachable, you will be feared, but not respected. If you are shown to care about those you lead, your team will develop loyalty and drive. Which do you prefer?