>If you ask a complete layman to design a FPS, he'll have to do so from the ground up and take nothing for granted.
And his game'll be shit because he'll be missing all the important lessons that have been learned over the years by other devs. You'll end up with something like Elite: Dangerous, where you get a bunch of people who are very skilled programmers, artists, musicians, etc, but who haven't touched a video game in the decades since the last Elite game before that and don't have the faintest clue about what makes a game fun and engaging.
And what they then churn out is a very pretty, very technically impressive game that's not remotely fun because they don't know shit about games and they haven't learned from everyone else who came before so when they try to reinvent the wheel they come up with a square instead of a circle and it's just as awful as you'd imagine.