Most demonizing of groups of people, in terms of stereo-types, is connected to projection. A stereo-types creates a one size fits all (all religion people are hayseeds). Any rational person knows this is irrational and illogical, since there are more than one size to any demographics. For example, there are some religious people who exploit the flock for money. Those who are gullible and end up exploited do not fall into the group since losing does not equal gaining. The stereo-type, on the other hand, illogically makes people victims and criminals at the same time, which does not even make sense.
What bothers me is only the atheist claim science and logic as their guide, and then create stereo-types and call this rational. Religion does not claim it is rational, which show a notch above in terms of objectivity to reality.
The entire situation comes back to projection. Projection is an unconscious process, where that which is unconscious, can be made conscious, by appearing to come from the outside in the environment. The demonizing is connected to the shadow side of people. Jesus said, people can see the speck in the other person's eye (projection) but not the log in their own (shadow projector in their own unconscious mind).
A stereo-type is a good litmus test of projection, since without the projection, one can logically infer one size does not fit all. But with the projection active, this movie of the imagination, will overlap reality, and make one size appear to fit all.
Many arguments between atheism and religion never resolve because of the assumptions that one size projections, from each side, fits all. The other side, can see all the exceptions and thereby know this POV is not even rational. What helps to justify and perpetuate many stereo-types, especially on the atheist side, is connected to the acceptability of statistics. Statistics is based on averages, deviation from averages, and odds. This makes any clear cut division between one size fits all, and many sizes, fuzzier, since odds allows for overlap, using low odds conditions. Statistics is a powerful tool, but like a hammer in the wrong hands, which is also a powerful tool, one can use it as a weapon to control and manipulate.
For example, if someone says drinking alcohol will result in liver damage, this is a stereo-type. It is true under certain conditions, but one can also show more exceptions than the claim of the stereo-type. If we add statistics to this stereo-type, which spreads the odds over an average imaginary person, and does not address specifics with probability=1.0, it now seems like all are at risk. Jesus would say love your enemy thereby learning to remove the shadow projection with a better projection. This is not taught in atheism since propaganda makes use of this of this tool/weapon to make one size appear to fit all based on the laws of chance.
The human mind is the last frontier of science and once it is understood, this will all go away.