From my perspective, there is a bit of an American law enforcement culture problem. Broadly speaking, I see it as quite a bit overly-militaristic / "them vs. the bad guy" oriented, and too little oriented towards the dull community service type things that in reality is more likely to make up most of a police officer's job (http://www.economist.com/news/united-states/21649507-when-la...). This explains much of the other problems, such as overly-aggressive behavior that I've personally only encountered from American cops (vs other Western nations), and often over-aggressive prosecuting where there is too much pressure to convict.
None of this necessarily reflects anything on individual officers at all. I've encountered all kinds, and broad, sweeping statements about "all cops" are going to be wrong. However, nothing will change to improve law enforcement culture if statements like the above are perceived as "anti-cop". Sadly, that sometimes seems like what happens in any debate on American law enforcement...