I disagree vis-a-vis stereotypes. I personally subscribe to the idea that in a society constructs do tend to serve a specific evolutionary purpose. That is true for god, society, or stereotypes. They exist in ways that may obscure their purpose, which is ( was? ) tribe survival.
<<This is significantly complicated when considering that stereotypes weren't created in a vacuum, either.
Absolutely correct, they exist as a result of observed facts and carried down as memes throughout society at large. You can question their accuracy, but there is a reason they exist and thrive.
<< which still doesn't mean they are good predictors of individual behavior
They are good enough for an individual predictions, which is all an individual is concerned with. The issue starts when it is being used more broadly.
<< If 50 years ago a bunch of the population believed that a certain class of people were more likely to commit crimes, and as a result more of those people tended to be arrested, then looking at those statistics today in isolation seems to "prove" the point that this segment is more dangerous.
Ok. Lets say we forget history for a moment. There is indeed an argument to be made that data may not be.. accurate ( but that also opens the question of.. is that accuracy zero ?). What about current statistics of shooting incidents in Chicago? Are those also biased, because they happen to show similar pattern ( I think we can agree shooting people is a bad thing and likely dangerous and those involved likely belong in prison -- self defense and similar being excluded )?