Yeah I think it's more in line with what AuronLu said. My mother isn't afraid of the police; she's a middle-class white woman living in a comfortable semi-rural neighborhood getting most of her information from the evening news. (She is fortunately smart and liberal-thinking enough to disdain Fox News, but even the more neutral news outlets have been very patchy and one-sided with their reporting. Most of what I've learned I've learned from sourced reports on tumblr, and I'm more inclined to believe them than what's presented on the news, because they're unfiltered by media bias.)

I think she and other people are doing it because it allows them to be willfully ignorant to the real matter at hand, and turn the focus away from "some police are killing people because our system is that messed up" to "#notallpolice!!!" because it's more comfortable for them. And that is a dangerous, frustrating attitude to have.