Good analysis. I generally see stereotyping in a development
  psychology way: It emerges in full bloom in high school age
  (ages 14-18) and continues for some throughout life. Teenagers
  are trying to figure out their own place in the strata and at
  the time, they often believe the stereotypes presented by their
  peers [and reinforced by entertainment]. As far as their
  accuracy goes, well, its like many generalizations: it's like
  buckshot hitting a target. The good thing about generalizations
  like stereotypes is it's easy enough to go to a place of higher
  accuracy, but it's much more difficult when you are aiming for
  precision and not accuracy... which is why I don't watch
  documentaries. [they pull you through a very precise chain of
  logic which ends up with an "inevitable conclusion" that fits
  the logic of the arguments, but ends you in a place that's far
  from accurate.   This is also why for me, logic isn't king.
  [1]precision_accuracy

References

  Visible links
  1. http://icopiedyou.com/wp-content/uploads/2016/02/precision_accuracy.png