As much as I want to agree with you, I cant. They dug it up, they pumped the water out, they maintain the joint. No one would have ever, ever, evereverever found it if not for them.
I suppose they could just say "Anyone who wants to vist CAN visit, they just can't use our tunnels.
They're going to let it flood again soon, and I actually think thats better for exploration. A submersible ROV can go much further into the cave than people can.