Of course there are good and bad in every profession. That's inevitable because people are human, they make mistakes and everyone has a bad day.
We probably all know police officers personally, be they friends, family, neighbours, acquaintances, who are lovely people who do a fantastic job.
BUT (and it is a fucking massive but) there is a significant number of police who are shockingly bad - and because of the nature of their role, when they perform it badly, or incompetently, or are prejudiced against certain sectors of the population, it can have a very serious and significant impact. Whoever said school bullies often end up as police officers was spot on. Plus racism, sexism, domestic violence, serial infidelity (I've not been propositioned by many married men thankfully, but those that have were all serving or ex police officers), lack of knowledge or understanding of the law they are trying to enforce, misapplication of powers etc.
Those of you who feel the police always do a great job, act with the best of intent, understand and fairly apply the law - have a look at the Crimebodge stuff on YouTube. You should find it enlightening.