Most doesn't mean 95% or 90%. It means more than 50%, and from what I've seen and heard, that seems easily true.
And very sad.
There is a lot of cluelessness in general from white people about racism. Even from those who are horrified by racism. We assume other white people feel how we feel until we see very strong evidence to the contrary, and we so want to assume other white people aren't racist that we search for other excuses for them. That's being oblivious, but it's a kind of cluelessness rather than intentional or something we understand we're doing.
I remember going to a coffee shop and being behind someone in line, and being asked what I want, and my immediate thought was that the person first in line must have been being helped already, because there's no other reason someone would ask me what I want first. But I had just gone to anti-racism training and I thought about that, and I said, "She was here before me." The barrista said the other woman was already being helped, and the woman said that no she wasn't. I don't know if it was an honest mistake, or if it was intentional racism, or if the barrista was oblivious, and there's no way to know. I also have no way of knowing how many times in my life I've assumed someone in line in front of me must already be being helped if I was getting helped before them.
We don't always even see it, and we really want to assume other white people aren't being racist. I think we as a group really need to wake up and see the world as it is. Things can't improve until we white people work on that. There's such strong denial.
But anyway I think when white people read something like this, they might hear it as "most white people are racist" and picture someone thinking most people are intentionally and overtly racist, like white supremacists. They aren't aware of how the obliviousness plays out because, of course, they're oblivious. I've felt that obliviousness and I know how it feels.