When life sucks and things go wrong we often look for something to blame on days when we're not at our best.
People who have experienced mistreatment because of some general characteristic have an easier time finding targets to blame "racists!" "sexists!" "-phobes!" unreasonably for their problems. We're all unreasonable sometimes.
If I'm having a shitty day day and I'm not a racist myself... I don't really have easy generalizations to blame for my problems so I have to find more nuanced ways to be unreasonable. (and yes, I have had bad days full of unreasonable accusations to blame for my problems, they just weren't towards some hot topic issue).
There is this issue where movements to empower and unify have a tendency to shit to blame and divide. It's a tough situation.