Steretypes are more accurate and useful than you think
I don't know enough about thees things to know whether they've done their homework properly or they're making some fundamental mistake. But the conclusions seem right to me.
The key paragrah is this:
The evidence from both experimental and naturalistic studies indicates that people apply their stereotypes when judging others approximately rationally. When individuating information is absent or ambiguous, stereotypes often influence person perception. When individuating information is clear and relevant, its effects are “massive” (Kunda & Thagard, 1996, yes, that is a direct quote, p. 292), and stereotype effects tend to be weak or nonexistent. This puts the lie to longstanding claims that “stereotypes lead people to ignore individual differences.
In other words: Stereotypes are often accurate, and people are generally pretty good at knowing when and how to apply them.
They know that they are generalizations and may not be true of everyone in the group, and when there's better, more accurate information available, they know to use that.
Sounds to me like stereotypes are a pretty darn useful tool.
And hey. Whether you like it or not, people use stereotypes all the time. I bet you do it yourself.
Rather than beating yourself or others up for that, just appreciate this wonderful tool that we have at our disposal. It's not going away, no matter how much you want it to, because it turns out to be useful.
In the words of Byron Katie: When you fight reality, you lose, but only 100% of the time.
I bet if you looked at the data, most of the people who are upset about other people's stereotypes are themselves stereotyping the people they think are using stereotypes. Oh, projection, how I love thee.