Orange boss checkpoint marker on maps

Have I miss understood something about this using thing? It seems to me that maybe 1 in 50 times I might have gone close enough to the boss area and not kill it, activating the checkpoint there and then later I can use the orange one to get there.

Why can't the orange boss checkpoint be used to go to the boss checkpoint regardless of whether or not you've uncovered the map fog there? That would be so nice.