Onuoha, who was the subject of racist chanting during the Under-21 tournament in Holland in 2007, believes that the nation's fans will not change.
The Queens Park Rangers defender told The Sun: "We aren't dealing with normal people here. If we were, then they wouldn't be dishing out the comments in the first place.
"You can only truly punish someone if they accept they have done wrong. I'm sure a lot of these people who gave out abuse would genuinely believe they've done nothing wrong. We know they have. But these people still live in a time warp.
"They think there is nothing wrong with their views. They believe what they are spouting is right. So do their mates and colleagues, and people sitting around them. No fine or ban is ever going to change that."
UEFA confirmed on Wednesday that both the English and Serbian Football Associations will be investigated for their parts in the incident.