The balcony is not advertised. It was the only opening in the room (no additional windows).

To be clear, they could give me some more logical explanation and I would not push it on (local policy, structural problems, ...), but I am very angry when someone makes a fool of me. I was in hotels with similar balconies and there were never any problems (eg Bristol in Vienna, Sheraton Diana in Milan (at the reception they asked me if I wanted to open the balcony), ...) I confronted them about it, but they still persisted that it was Marriott's general security policy, not them.

Is there any Lurker who can give more info and confirm / reject their explanation.