That's absolutely right, that a balance needs to be maintained.

If this were last year, I would have agreed with you that openness is more important than safety; however, just this month I taught a two hour lecture on engineering ethics and I now have a much better appreciate for why not everything is open. As engineers we're ethically bound to hold the safety and welfare of the public as our top priority, which sometimes will conflict with our other values, such as openness.