There is something about high school seniors and low-level code like this. From numerous observations over the last 15 years or so. I think it might be because your first 5 years in the profession serves in part to teach you what technical issues to be "scared" of, and high school kids haven't learned that yet.
I certainly did my lowest level stuff (building PC ISA hardware from scratch) in high school. Mainly it was out of necessity as I didn't have the money for the real hardware. Other folks I've known who have gotten into ASM in high school did so for game cracking/cheating/modding, also a form of necessity.
Any* sane professional development organization is going to try to minimize the amount of time their developers spend writing ASM by hand. There's almost always a higher level tool that's more productive.
* Actually, I worked at a place where the main DOS product had been hand written entirely in x86 ASM. The sanity of continuing such a practice into the 90's is an open question. Rumor had it that even the Windows versions of Wordperfect were written in ASM.
The thing high school students have is time. Time to experiment, time to go deep, without external pressure. Once you are in University or the work force or have dependents, the pressure is on to get results, and you no longer have time.
The irony is that the applied pressure probably doesn't produce a superior result to being left to your own devices.
I entirely agree - as a high schooler, I was very, very good at reversing.
It's helped me a lot professionally, actually - I'm much faster at debugging compiled languages than my coworkers are, and the mental patterns I developed while peeling away the layers of control flow in disassembly map very well to understanding large code bases even when I do have the source.
I think it's mostly a function of time rather than being scared, though - learning how to reverse takes quite a while, and once you've got a professional job where reversing seems entirely irrelevant (and even potentially dangerous), it's hard to justify taking the time to learn how.