This question can be answered in at least two ways. First, we can say that it is reasonable for police officers to arrest criminals for misdemeanors, because they have broken the law. The law is the law and should not be broken. Moreover, there should be consequences for lawbreakers. Without this relationship, the law would mean little.
Second, we can say that in a complex world such as ours, it is practically unreasonable to arrest people for misdemeanors. The reason for this is that there are not enough police officers to arrest all then people who commit misdemeanor crimes. More importantly, police officers have more serious crimes to address. Hence, to deal with misdemeanors all day long would be a waste of time, resources, and even hurtful to the public.
In light of these two points, what officers need is wisdom.