Well I can give you a very good example in terms how UE4 actually empowers me. At ShardLine we have Artists, Coders, Designers and so forth and its pure luxury to have that and create custom things. Now me being also a Game Design Student, and I literally am so bad in creating Art, I strive for the fact that I can reuse so many stuff and combine them into prototype levels for my bachelor and get a decent look. Lets be honest, yes we all love the blocking days :), but if a prototype level can be meshed together and also look mostly decent for testing, so what :).
But yes, people will use basic stuff from the engine and try to sell it, but honestly that guy will become perhaps the next big Sales Guy at a Financial Institution (some irony :)).
The thing is that bringing games to people is just another whole ball game that includes a lot of understanding of the market, the different models and how to engage it and also sustain momentum until you might need to change into a new model. And of course knowing people doesn’t hurt, next to some luck. Look at Epic, they needed to change their model to a new one, times have changed. (Though I still believe that it wasn’t only the notion to change to a more service-oriented company, but also because they really truly wanted something new)
Now with the example you are giving, that kid actually just does that what many will do, getting loud and selling something which isn’t truly unique or self-made. And that is something that is very true to live anyway because it is part of selling and buying. And that is something Gamedevs need as well. But also support from a Mediator. Epic can be that, if your game applies to their standard to be marketed.
Point being, even though I understand what you are saying and I also am not a big fan of it, what we can take out of it is, if that guy actually sells that game you might try to hire him to sell your game. As some people say back here in Switzerland, if you can sell Air, your are a true Salesman.