I doubt many people are against the idea of a specialized government role that provides protection services.
What they are against is:
* Thinking we can get that role by reforming existing police systems, given how opposed police systems are to such reform
* That these systems need the absurd budgets of police departments
* That the role requires absurd levels of protection for violent actions
* That the role requires armaments in the majority of cases
Going form police to a role that fits those criteria is going to start with not having police.