Why are navies reluctant to risk crewed ships?

Why are staffs reluctant to accept losses in crewed naval operations?

Trained people have considerable value, and casualties attract attention that drone losses do not.

Trained personnel have a value that staffs must consider before accepting losses. Casualties also attract public and political attention, while losses of drones do not receive the same response. This creates a difference between risking a crewed ship and risking an uncrewed system.