Imo, it's worth nothing. Their willful ignorance does not excuse the reality of the atrocity they support. And especially in this day and age of information accessibility, if they don't know it's because theyre choosing not to.

Ultimately, yes. In practice, though, we don't live in a proper information ecosystem anymore. I know plenty of people with their heads willingly shoved up their asses, but I also know good-hearted people who don't get it. I do believe ignorance is culpability, one some level. But not absolutely.