Which is the greater tragedy: the fall of an empire, or the end of your marriage? Is it more important to make a major scientific discovery, or to be a good parent to your child? It's a false dichotomy to say that fiction should only concern itself with one or the other; all of these issues are worthy subjects for fiction. Unfortunately, it can be hard to tell stories on a grand scale and an intimate scale simultaneously, and most fiction prioritizes one over the other. Science fiction has traditionally opted for the fall of empires and the scientific discoveries, but that preference is not intrinsic to the genre.
One of the writers who helped me realize that was Edward Bryant. The stories in his collection Particle Theory showed me that science could be used metaphorically to illuminate human experience, and that the personal could reinforce the "big ideas" rather than compete with them. I discovered him when I was in college, at the same time I first started reading writers like William Gibson and Gene Wolfe and John Crowley. They all expanded my ideas of what SF could do, but the one whose influence on my work is clearest is Bryant.
Read "Particle Theory," by Edward Bryant