Perhaps Bradbury's main purpose in "There Will Come Soft Rains" is to observe that no matter how technologically accomplished we become, humanity's overriding inclination is to wage war. And after the development of the devastating weapons unleashed on Hiroshima and Nagasaki at the end of World War II, Bradbury observes that the stakes in waging war have grown frighteningly higher than previous wars.
Bradbury also suggests that we, as designers of the technology that powers the story's empty house, may be reflecting our own diminishing humanity. The robots who first let in the whining dog and then clean up its carcass are "angry mice, angry at having to pick up mud, angry at inconvenience." Of all the human emotions to assign to robots, Bradbury chose anger, not compassion.
Another "convenience" of the house reflects man's diminishing humanity. A robot voice reads aloud a poem at day's end; literature is, ironically, considered a discipline of the humanities, yet it is left up to a machine to coldly recite what perhaps Bradbury felt should remain the domain of the human voice.