Do you honestly consider Muramana an active? lol
It's a passive that you can turn off at your whim.
You interacted with it. It was an active item. It was something you controlled. Now it's something that just goes off until you hit a certain MP.
I really just don't like the way the game is going with these item changes. More and more of the items are controlled by things out of your hand, or at least less controllable.