Why do people still respond so immature to stuttering?

Why do people still respond so immature to stuttering? I’m 22 and I have a stutter with visible head locking my whole life, it’s made it so that I’ve been bullied alot my whole life because of it, and honestly it makes me really angry just thinking about how ignorant people have been forever. Even to this day, grown adults twice my age will smirk and share glances. Not to mention it makes it basically impossible to approach women without instantly getting laughed at. Hate my damn life 🫣