Since I started getting migraines I have really gotten to hating how every "cool" video has to include bright flashing lights. Yeah bro, thanks for leaving me with headaches and distorted vision for the next hour. And like that's just with migraines, which won't kill me. Imagine what it's like for someone with epilepsy. Like, bro, your video about your new OS could literally kill someone by accident. Coooooooool.
Edit: just throwing some percentages in, Wikipedia (LOL) says about 0.5% of the world's population have epilepsy, and ~15% get migraines. That's a LOT of people. And with migraines it's mostly women too, so it becomes a gendered issue.