There are a number of good reasons to choose a console over a PC.
The enclosed eco system
Having friends on there
Harder to f*$% up
There's also a number of poor reasons to choose a console over a PC.
One of them is branding and fashion. As a kid I rated McDonalds over actual hamburgers because of this. The McDonald hamburger is mediocre at best, but it was on TV and COOL.
I don't know if Xbone/PS4 are cool the way McD was cool to me, but there are better hamburgers and better PCs out there.
You should check with your kid whether he just saw too many xbox commercials.
Extra warning, they announced the next two consoles in this xbox one generation yesterday, so if this is a major driver, expect to get bugged to upgrade soon.
There's reasons that are switching columns.
The exclusivity is one of those. Microsoft is saying (not completely walking the walk yet) that they're implementing cross platform play. What you can play on the xbox, you can play on windows 10. This didn't use to be the case and there's still exclusives out there (although the example used earlier, quantum break did come out on W10 on the same day as xbox) but not as many.
There's also the place the system has in the house. Most PCs are in a corner somewhere, whereas a console hooks up to the TV and can generally be found in the center of the living room.
This effect can also easily be achieved with a PC, wireless controllers and a smart TV
The controller can just plug into a USB port, no worries.
The kinect . . . . I don't know.
8th gen console (xboxone and ps4) exclusive games:
https://en.wikipedia.org/wiki/List_of_video_game_exclusives_(eighth_generation)
vs
complete list:
https://en.wikipedia.org/wiki/List_of_Xbox_One_games