That's the cover story, and it no longer holds up.
Police show up to close out trouble tickets, not to enforce laws.
I have written about this specifically:
https://sneak.berlin/20200628/the-problem-with-police-in-ame...
The police in my area spend most of their time enforcing traffic laws, responding to domestic disturbances, etc. Murders are taken very seriously, regardless of who was murdered.
Based on my actual experience living with police in a boring suburbia, your article comes across as completely out of touch with reality due to no actual experience.
Have you considered that the reason there isn’t an explicit law that police have to respond to a given call is because there is immense political and therefore organizational pressure for them to do so? The county sheriff or the mayor would get voted out if that was a pattern in our local government and then police leaders would get fired.