Definitely a shot worth the time and effort, I think. It has a somewhat eerie feeling to it. People walking into your shots can be annoying, but I try not to blame the people. They probably have every right to be where they are and if I don't want them in my shot, then it's up to me to patiently wait. Also they're oftentimes just oblivious, or thinking "I'll just quickly pass by so the photographer can take a picture", or they don't want to awkwardly wait if they think you're going to be there for 5 minutes taking pictures.
Cheers, it was a pretty eerie place to be, especially entering the isolation cells and seeing what it would be like stuck inside. Not fun, is the least I can see. I agree with your point on people having the right to be somewhere, of course they do, and that applies for pretty much anywhere and everywhere. However, and without getting into a massive rant, common courtesy would be nice sometimes. If people don't see you, then that's fair enough; can't hold it against them for not knowing. It's frustrating when there are people who see you're lining up a shot, and then just continue walking into it. After waiting to take this, it was probably all over in 10-15 seconds. It's like taking a photo of a couple, and then having someone walk right between you and the couple as if it's no big deal. Anywho, photo was achieved, end rant haha.