Yeah, I'm also voting for the second option (America failing as a civilization).
Yes, there are many terrible cops should not be cops in the US, but the majority of them are actually not terrible. You have to realize that cops are thrown into an environment where they might be genuinely in fear for their lives a good part of the time.
Think about the current situation in the US:
1. Almost no gun control, which means that virtually anyone anywhere may be armed to the teeth.
2. Poor access to education for large segments of the population, which means that the population at large and the cops don't generally have a very good or high-level of education, which, in turn can lead to elevated levels of violence. For instance, there was a recent study that demonstrated a pattern that cops with only a high-school education are more likely to use force than cops with a college degree, and most cops don't have a college degree.
3. There's a dangerously low amount of social services, and a particularly egregious lack of certain services like public psychiatric wards (I understand that this was thanks to Saint Reagan). This means that there are many honestly, completely crazy people roaming the streets. I have personally seen many, many, many schizophrenic people running around yelling at themselves, or making other crazy noises and gestures on the streets. It's very, very sad.
4. Historic racial, and class tensions in the US, which means that people already come into this with pre-conceived notions about the other.
5. America has a LOT of poverty. This amplifies every problem listed above.
Put all these factors together and you have a recipe for disaster, which is exactly what we have been seeing. I don't blame the cops in general - like I said, there are some bad apples, but they are generally in a very, very tough situation