I guess kids suggests someone quite young, but my impression was they (xbox and playstation) were built for people in high school and younger, which is why the product makes sense. As OP pointed out, if you were 35 just getting into gaming you'd just buy a desktop.

Consoles like Xbox serve parents who aren't tech-savvy enough to hunt for PC deals and don't want their kid to have free access to the internet.

For what its worth I used to work on a parental controls app startup and this is a consensus I found talking to customers (parents), they like their devices to do one narrow thing so they can control how their child spends their free time. There are of course adults who play it but this is the core of the market, and the strongest value-add in my opinion.