Because white pride is already every other day.
Because you're already assured on a daily basis that your skin color and race and heritage is correct.
Because you open magazines, watch TV and movies, see posters of people who look like, who assure you that you are beautiful because you look the same as them, that you matter, that you are represented in the world around you.
Because you are taught the history of your ancestors in school. Because you can name most of the countries in Europe, but you can't name most of the countries in Africa or South America. Because you know the rough history of the leaders and types of government of various European countries, but have no idea how Africa, Asia, and South American countries are governed. Because you know the names of a few Native American tribes, but would have trouble naming where they were located, how they governed, or whether they still remain. Because you assume nearly all Africans live in poverty and all Native Americans lived in teepees.
Because you know the advances that were made by your people. You can rattle off several white inventors, scientists, etc, but when it comes to successful Black people of history, you're pretty sure that George Washington Carver invented...I dunno...something with peanuts?
Because the only thing you fear when you're pulled over having to pay a lot of money for that ticket. Because the worst name you get called is "hillbilly", or "white trash". Because you've never been refused service, or followed home by a man on a cell phone, or asked to prove that you're a legal citizen.
Because you've never been called a terrorist. Because when Dylan Roof shot up that church, you didn't fear retaliation because of your association with Christianity, or because you were white. Because 6 million of your grandparents weren't gassed to death because of their religion. Because you're not forced to take your cross necklace off in order to work.
Because when you move into a house, the neighbors automatically assume you're a good family. Car dealers don't automatically assume you have bad credit. Employers don't automatically assume you have a rap sheet.
The world already celebrates you. Celebrating others doesn't hurt you. Shut up and stay in your seat for a change.