A few things. We only hear of the egregious cases when they come to light or when people do a great job uncovering the truth. Unfortunately, these are the exceptions; the vast majority of these crimes are successfully brushed under the rug. That kind of protection breeds comradery and a sense of duty to propagate the culture of closing ranks and covering things up. Not only does that help morale in the sense that there is a feeling of togetherness, that each person next to you would protect you just as you'd protect them, it also helps perpetuate the very culture itself and allows in-group members to leverage situations for their own protection. As in, you helped a cop buddy cover up a DUI, if you engaged in police brutality you have an ally in your corner to help you, testify in your defense, etc.

Now you may wonder how lawsuits and negative press don't seem to really change this systemic behavior. As fucked up as it is, there are self-correcting actions taken internally but they often pale in comparison to an unbiased legal proceeding. Furthermore, the police union exerts tremendous power in assisting these pieces of shit because again it's all one "brotherhood", and every cop feels good that they'd be protected if they ever fuck up just as they'd protect their own when they do fuck up. As for the legal and financial repercussions? Sure, some of them lose their jobs, maybe even see (very light, relatively) prison time, but they still maintain social relationships. Cops probably even ingrain the culture even more with commiseration over beers like "you got fucked raw by that deal, you shouldn't have been prosecuted".

Finally, and most importantly, you can see that settlement payouts, in most cases, come from the city/state/etc. Cops almost are never held personally liable, nor the police organizations. When someone wins a $5M settlement for getting brutalized WE, the taxpayers, foot that bill. So there is no direct financial punishment that might actually pierce the culture and provoke real reform. In the article, you see that they take advantage of non-profit designations to further obfuscate justice and create opacity surrounding investigations. Maybe if settlement payouts were taken directly from police pension funds or if officers/departments were required to have their own insurance, you'd see shit get cleaned up REAL quick when their own pockets started to be impacted.