The Guardian is powerful. The Ghost is Fragile. If the Guardian dies, the Ghost is on its own. You realize it is generally concerned for you more than itself, right?

Fragile ghost took centuries finding me, taking care of itself in that time. It just doesnt want to see all that time floating, scanning and running leaving little ghost pellets go to waste

Last time I checked, your Ghost was about to eliminated before he found you. Do you notice how many Ghosts have been destroyed? A Ghost and a Guardian share a bond. A Ghost cannot fend for itself. A Guardian would not be able to do the things he/she does without a Ghost. They are necessary for each others existance. Eris Morn lost her Ghost. Look how she turned out.

Look how the Queen turned out without her ghost.