One of the problems with a police state is that people lose faith in the police and government in general. They stop engaging police in a friendly fashion. They don't take matters to court assuming they will get justice. They become closed communities that move out of the reach of social services. Just think of how poor communities think of talking to the cops- it's "snitching" and its' highly discouraged.
Most of the cops in this country are good people, but as they start responding to every call with a SWAT team, people are going to stop wanting to use the police. Responding with a SWAT team escalates the level of violence, it's the opposite of keeping the peace. Hardly a week goes by where we don't hear about overzealous cops that get called to keep the peace and end up shooting someone. Just last week we saw an instance of a cop shooting a teen that was restrained and tased because he "didn't have time for this.". The numbers continue to add up.
If when you call the police it increases the chance someone will be seriously injured or die, then people lose all faith in the police. When people lose faith in police, the police lose the ability to do their jobs effectively. It's counter productive to it's goals.
As well as being counter productive to the goals of keeping the peace, it's actually harmful to public safety. People begin seeing cops as a greater threat than criminals. In some cases, that belief certainly has merit. The number of people shot by police in the US is much greater in this country than most other first world nations.
Lastly, the methods used by the police state aren't effective at achieving their stated goals. After 25 years of dropping crime rates, we are again trending upwards. Very restrictive gun laws in big cities like Chicago and Baltimore aren't stopping murders. Collection of all of our phone and credit card data isn't stopping terror plots. Deploying battle-ready vehicles in hundreds of US cities isn't stopping crime. It's alienating the populace from the government.
Stay safe out there!