Court after court after court has ruled that the police have no duty to protect.
Ask any one of thousands of people who have been "protected" by the police when an ex-spouse, ex-lover or stalker has repeatedly violated a protection order.
You may need a ouija board...
It has nothing to do with a "duty to protect."
It has everything to do with giving the police the legal authority to break down your door without a warrant if a family member calls the police and reports that you have made suicidal threats and are not answering your phone.
If suicide was legal, the police response would have to be: "So what?"