Because for so long, LGBTQ+ people have been made to feel ashamed for who they are as a person. Society has scolded them for something they can’t help. It’s not about being “proud of their sexuality”; it’s about no longer being ashamed, and showing pride in themselves. And for all of the people who came before that had to suffer, or lose their lives, for being “gay” or “homo” or whatever, we celebrate their sacrifices and achievements.