No doubt, one must mind their 3-year-old, but have you had to watch a 3-year-old? Luckily, ours isn't a crazy adventurous one. Still, we are just now getting to the point where we can watch her approach a street several paces ahead of us, only ready to spring into action if she forgets about the 'danger of cars' thing. In contrast, her same-age cousin is still apt to play real life Frogger if he isn't physically prevented from doing so. If you knew that guillotine elevators were an environmental hazard, you'd have to adjust. I'm just glad I don't have to.
I'm the proud father of a quite internationally travelled 6-year-old, so I've definitely had my share of hazards. We lucked out on the kid lottery and have a fairly thoughtful kid, so it's been ok. I could definitely see sweating a bit on these elevators at first glance, but once you get the idea that you step in and make sure you're all the way in, it doesn't seem too bad. Although all of this might be a moot point. I'm curious where these elevators traditionally are. I'm sure they don't tend to put them into daycares and things like that. If it's an office setting, your exposure to kids is probably fairly limited.