Riddle me this

Ah, what have we here! An instruction not to use this door. But is that not another door right there to the right of the one with the sign posted on it? Perhaps I could just use that door and proceed as originally planned. But that's too easy an answer. Surely, what they mean is they would like us to avoid what is behind the door and use some other, unseen in this photograph, door and navigate a different path entirely. Otherwise, why would they both be shut? Right. That must be it. Only some smart ass would assume that "other door" means "other door serving the same purpose, since they're right next to each other and are, in fact, two halves of the same door". Very well. I shall turn around and find another way to my destination. It's somewhat inconvenient but I respect your request for me to avoid whatever it is that lies down that hallway behind the door in question.

Unless some dumb ass just neglected to take two more seconds and draw an arrow indicating that the door on the right is just fine. Oops. Sorry.