No, they're actually in my scope of concern, that is the whole point of your article. The reason they were brought into my scope of concern is that a lot of people had a use case for styling custom scrollbars. I have a use case for it myself. If you're saying "don't abuse your ability as a developer and make inacessible websites" then yeah, okay. But taking options away from people because they might theoretically make bad moves with them is not a good strategy. If you took away every CSS attribute I could use to make inaccessible websites, we wouldn't have anything left. You'd be surprised what I can mess up. Better to teach people how to do it right and why.