I'm not so sure lack of distractions makes that much difference. I think on my C64 it was frequently the case that we'd switch games every few minutes. We were easily distracted with or without something specific to trigger it.
But these computers were simple enough to "mess with" and get a mental model of the whole. By the time I was 7-8, I started "experimenting" with pulling chips out of sockets (to my parents horror) and seeing what happened if I put them in different places (...). If you even could have done that on modern machines with almost everything surface mounted, you'd fry stuff. With those old machines that was usually fairly hard. Amazingly, I never burned out any chips that way. The simplicity encouraged meddling with things in a way that is harder to see younger kids do with most modern computers:
PCs are outright dangerous to let a young child dismantle on their own - whether or not you disconnect power (I'm afraid my C64's were more than once opened up while connected..); machines like the Raspberry Pi are simple and safe enough, but there's nothing to do inside them. Likewise for tablets and smart phones: If you manage to disconnect the display without breaking anything, you're pretty much at the limits.
If you try to break into the black box as a child, you're faced with an image of something that is way beyond your comprehension.
The C64 and similar home computers, on the other hand, had clearly labelled diagrams in their manuals that even a child could understand. You'd open it up, and you'd see what the different things were, and you could tinker (at least if you didn't tell your parents) and see the effects.
It seems like it is harder to become "independent": Children learn a few "magic incantations" to get to the familiar things, and the knowledge required to bridge the gaps where exploration yields results that encourage further exploration seems higher. Or maybe that's what it looked like to our parents too.
A few years older, I soldered wires straight onto the pins of the CPU of my Amiga. You could make a "pause" switch and reset button easily that way - you could solder it onto the bus exposed on the left hand side of the A500's too, but I had a hard drive attached there.
Speaking of hard drives, considering the article mentions demonstrating floppy drives with the cover off, of course I did that with my 1541 drive for the C64 (and test what happened when moving the IO chips between the 1541 and the C64 - they're "almost" the same model; enough so that the C64 at least will run; same for the one from the Amiga - their differences are small enough to be inconsequential for most programs), but also with my first (20MB) hard drive out of necessity: I bought it used, and within 6 months it started having problems starting up. The solution? Open it up, and give the motor a helping hand spinning up the platter - after that it worked fine. The drive survived another two years I think after that.