It is in extreely difficult terrain, it is very low grade, it will have a huge capex (tunnels do that). I am not sure it makes a mine right now. With so much gold I am sure they will find a way but all they do is make it bigger (more oz) not better (more profitable) which is why no major is taking a crack at them.
I don't think they are under valued. I think they are a long ways from a mine at KSM, I don't know couragous lake.