I believe it’s basically tribalism. If you’re living in a tribe in one of your stronger/more influential members takes advantage of a weaker one… Well the outcomes are: expel or kill the perpetrator, weakening the tribe and losing the benefit of whatever that person did, or ignore or otherwise neutralize the victim, who’s presumably less valuable than the perpetrator, otherwise they wouldn’t have been taken advantage of in the first place. This is also ignoring any power struggles that might kick off too.

We basically aren’t as evolved and civilized as we think we are and are still using primitive tribal thinking long past the time where it’s useful.