It's not because I'm racist. It's because I'm not. When you celebrate the achievements of people like George Washington Carver, Thurgood Marshall, or Martin Luther King, because it's Black History Month, you're actually degrading their achievements in favor of their race. Celebrating Carver because it's black history month is getting the priorities backwards: you're saying "This is a black man who was a genius." You should be saying "This is a genius who revolutionized the food industry." That he is black, if mentioned at all, should be a passing afterthought.
If someone's achievements are worth noting, their skin tone--and a month to honor that skin tone--should be irrelevant. To suggest otherwise strikes me as bigotry.