The computer I grew up with was isolated. If I broke it, I had a broken computer. I could take my time fixing it. Nowadays, a computer is connected... to the other computers in the house, and the entire internet beyond. If my kid breaks his computer, he might get in all kinds of trouble. I can't let him play around and fix it if it breaks, for the same reasons I don't let him play around with something plugged in to the mains electricity as a way of learning about electronics.
I'm also not going to let him wire up the x-box, because I know that a busted HDMI connector that broke because I was letting my kid plug the thing in is unlikely to be covered y the warranty.
As for the XBox, couldn't you just supervise while your kid hooked it up? Hand him/her the parts, tell him/her to go to it and you'll answer questions and keep an eye on things so he/she doesn't break anything but otherwise leave him/her to figure it out.
"If you think the cost of education is high, try the cost of ignorance, it is even higher!" https://www.youtube.com/watch?v=GQENHCkiMBU
That's exactly how I learned this stuff. The damn game wouldn't play, so I had to make a boot disk.
Then I learned to make a bootdisk with a menu system called from the autoexec.bat - cos I realized that several games had the same emm386 requirements. And now I program things.
Ahh good times... good times.