Insulting a Public Officer is not a legitimate reaction to Authority and in principle is anti-democratic. Insult is a kind o moral torture to which only cowards recur and doesn't change the fact that ignorance of the law is no excuse. The injury to Public Servants is an aggravating factor.
Even though many officers seem to see disrespecting or insulting comments from people (unfortutantly often black males) as a threat and use that excuse to beat up innocent people with their fist clubs or with tasters and then people all over the place defend them because they were disrespected, which apparently some people see as a threat.
There are already many laws in the police's arsenal under which to prosecute citizens who refuse to cooperate, including resisting arrest, assaulting a police officer, obstructing a public official in the execution of his duty, unlawful assembly, nuisances committed in public places, and other public order-related crimes. Passing such a law will not only overlap grounds covered by these laws, but also lead to problems concerning the definition of 'insulting', which will lead to much unnecessary controversy and debate, such as whether a specific word or phrase counts as an 'insult'. It is unfeasible and unnecessary.
I know that insulting people is really hurt for others but it's not such a big deal because if we insult to our friends or our siblings. We can get an apologies. But if we insult to an officer, i think we can get an apologies too because people need to treat police equal like others.
Although it may be true that it is wrong I still think it shouldn't be classed as a crime and there can be an uncontrollability in people to be insulting due to their situation they're in. Also a reason for why a person might be insulting to an officer could be that the officer himself has approached the person in a vile manner that causes them to be insulting.