You're not really learning about the canyon, you're following 2 city guys who hike the canyon from one end to the other. It's more of a home movie than a true exploration piece in my opinion.
Also, as someone that's hiked the grand canyon, these guys were dangerously lacking in preparation and decision making. Their initial guide, Rich, had to stop them on their first attempt, and even on the second they are largely not educated on how to hike the canyon's unique dangers (heat, water, weather, etc) well, take dangerous/not necessarily interesting routes, and make numerous questionable decisions that could easily have gotten them killed.
I think we could have gotten a much better feel for the canyon's many wonders without the slog of hiking from one end to the other, but to do focused treks at key geographic, historical, and visual locations.