Not so much willful ignorance as backwards reasoning. They desperately want to believe the world is fair and they earned whatever success they've had in their lives, so they adopt beliefs that lead to those conclusions.

I struggled with it a lot in my 20s. If you've grown up with the idea that the world is basically a pretty decent place, it's hard to accept how fucked up everything is, so there's a natural tendency to try to explain away the things you learn about so you don't have to confront the harsh reality directly.