You're forgetting that a whole string of breakthroughs are all fairly recent (like in the last decade). Everyone, including the pro's, is treading new ground.

In that context anyone can make progress in the field, as long as they understand what they're dealing with.

Better regard mr. Carmack as an X factor. Maybe the experts will leave him in the dust. Or maybe he'll come up with something that none of the experts cared to look into.

Lots of scientific fields have seen breakthroughs in the past decade. Doesn’t mean that any random smart person can jump in and start doing groundbreaking research.