It's not, and the fact you can't see the difference says a lot about your inability to grasp why people think Bernardo's done something wrong.
Was everyone who owned a golliwog racist? No. They were just racially insensitive dolls and a lot of people who owned them were ignorant to the fact they were offensive until it was pointed out.
The same is true of making a joke. You can make a joke that's racist through ignorance or overstepping the boundaries or coming from a culture where the lines are drawn differently without holding racist beliefs.