The Cloud striders look at their own lives differently than those on Earth it seems and even with Nimbus coming off cynical, it would’ve gave Nimbus a better send off than Rohan. Rohan could’ve looked at Nimbus and realized that there isn’t someone else to teach that wasn’t introduced into the story, frightening Rohan to seeing he may not even be around to teach a new generation of Cloud striders. Rohan could’ve easily become frightened, truly eclipsed in teaching Osiris and our guardian what it means to be a Cloud strider, with everything behind ideals and the actual sacrifices. Rohan then could’ve looked at the mural of the youthful and cheery Cloud striders, realizing that even in defense of Neomuna, war itself is terrible and there should be peace, even to the point of closing off the entire planet to the rest of the universe, similar to what Savathun wanted in a sense. Rohan’s character was truly wasted.