I’m a constant checker of my zip pockets as well; I often check just before I get on the ride numerous times and even when I’m secured in, I do a final check before we set off. Heck, I always get told by my parents that I’m being too paranoid constantly checking my zip pockets are done up!
However, I’m not sure it’s fair to penalise people for forgetting to secure small loose articles. We’re only human; we all forget things, and even if it’s seemingly second nature to us, it’s still possible to forget these things! In terms of why the park reminds people to secure their loose articles, it’s probably a way to help people to remember to secure them, and that there are holds provided to secure them in.
When you’re excited for a ride, especially after a long queue, I think something like securing loose belongings can sometimes be easy to forget or not take into account, in fairness!