Nurses, especially those working within a hospital milieu, are every bit as face-to-face with the worst of society that cops are. Except we don't have badges, guns, handcuffs, or legal authority. While there is some recourse that can happen if you're assaulted by a patient (which I have been, many times), in terms of the patient being moved elsewhere, being kicked out of the hospital (takes a lot), or arrested (takes even more), the amount of work that is demanded of nurses in a hospital right now plus the legal duty we have to make sure that those tasks/orders are taken care of means that it usually isn't worth our time to make anything happen other than the patient being assigned to another nurse. And sometimes that isn't even worth making happen because of the amount of paperwork/reporting involved. Even getting a patient who is unable to reason (DTs, for example) in restraints adds a huge task burden to the nurse who is taking care of them. Sometimes I'd rather just not turn my back on them again than have to deal with the constant assessment and paperwork.
I worked trauma/critical care for ~7 years or so. I've been kicked, punched, spat on, pissed on, called every gay slur in the book, illegally recorded, sexually assaulted, and threatened with a knife while in the course of a shift. Not once did I ever see a patient put into violent restraints (meaning minimal voluntary movement, facial restraints, that sort of thing), nor did I ever press charges on anyone who violated me. I also don't know anyone who did. No one has the time, and a lot of people lose their mind while in the ICU, legitimately and otherwise for whatever reason, so there's also always a thread of "well maybe they don't know what they're doing." Administrations love to talk big about taking these sorts of things seriously, but the underlying attitude is, as always, deal with it.