"Most of the time this young person thinks their qualifications come from the fact that they really, really, like to play video games a lot; and I mean like a LOT."
It gives you an opportunity to help them discover things they may be passionate about. Many times (not always of course) it isn't any game they like playing alot, it is a particular game or genre they like. The goal of exercise then is to think about what features or mechanics of that particular game make it so fascinating, and then looking for that same feature/mechanic in something that people pay for [1]. Is it the economy? Solving the mysteries? Developing the story line? Role playing and acting? Devising tactics? Optimizing dozens of variables? All these things are mechanics in computer games that can be found in non-game activities.
It may be that the kid likes all sorts of games, but help them to see the thing they like over the delivery mechanism and they can make smarter choices down the road.
[1] I did know a guy who liked playing WoW a lot and supported himself by selling gold and various and sundry rare and epic items. Again, more the exception and not the rule.