At the heart of many of society's "-isms" is a laundry list of stereotypes that seek to characterize a group in ways that both provide an easy, if inaccurate, method of describing that group, while also confirming already-inherent biases against it.
While some stereotypes may be born out of some facts about a group, they most often are limiting and harmful, relying on cultural beliefs that do not reflect the lived experiences of those who exist within a group.