Well if there's a weapon involved - Unstable person waving around a knife in public for instance, which is fairly common - It's automatically an emergency and PSR isn't involved (Which ironically means it has a much lower response rate, as the cops here are bad at showing up in time for emergency calls). I think the police are opposed to it because 1) It's money that might otherwise go to PPB, who already get millions of dollars in budget expansion every year and more importantly 2) It puts the lie to the myth that you need an intimidating security force with weapons to respond to all incidents when e.g. an unarmed 40 year old woman can diffuse a seemingly violent individual possibly in psychosis by offering them a peanut butter sandwich, asking them when the last time they napped was, and sitting down with them on a bench to talk about their feelings and issues for a half hour.