One of the reasons that Snyder is a good choice for doing these genre films long-term is that he’s found a way to maintain a work / life balance that gives him the energy, endurance, and optimism to keep at it.
His life partner / wife is with him, so the film doesn’t take him away from his family, rather his family is a part of it (his kids often have cameos too). Leading up to filming, he works out with his actors as much as possible, helping build a rapport with them but also building up his body and mind for the stress of the shoot. He does small fun little diversions like the Star Wars social media “feud” to blow off creative steam. And finally, participating in charities like the ALS Ice Bucket Challenge or National Bat Week, helps reinforce the values he was raised with and remind them there’s a world outside the bubble of their film.
A lot of other directors may start out or be acclaimed as genius above Snyder, but I suspect he’ll be less likely to burn out and build to greatness than others. [FN1]
[FN1] Some examples of possible genre burn out: Nolan peaked at Dark Knight, then was reluctant to return for Rises. In fact, the very reason they began to develop Man of Steel was because they were creatively stalled and needed a break from Batman. Raimi’s third Spider-Man film is generally poorly received. J.J.Abrams is not doing Episodes 8 and 9 of Star Wars, likely because the commitment would take him away from his young family.