Why is this a surprise? You see warnings everywhere about people who shouldn't ride particular rides for whatever reason, but they can't prevent people from taking the risk. The statement also says they have taken enhanced health and safety measures for the safety of guests and cast members. They aren't saying we're not doing anything so it's up to you. They aren't putting you in an intentionally dangerous situation.
They can disinfect everything in sight, wear masks, inform us of the risks, try to make people stay at a safe distance, but they can't make people have common sense. If you know the dangers of a situation, you make your own decision about the risks. I'd be interested to know how many people die by misadventure every year.