I don't think it's exactly necessary, but for me a lot of the time it just ends up... happening? Sometimes I'll have been working on something for a while, blink, and realize I've encoded my politics into my work without noticing. Ultimately, any articulation of emotion is inseparable from one's world view and ideology. The way I make a fictional society evil or the way you make a story cute or creepy depends on that individual ethic. Still, the emphasis you put on that connection is up to you, and not everything has to be a deep interrogation of the human condition.

Recently I rewrote a story about deep sea scientists trapped inside a dead whale. Is there ideological significance to the dead flesh's dominion over the living, the swarms of scavengers picking sinew off bone, the slow corruption of the characters the longer they hear the still-beating heart? Probably, but that wasn't what I wanted to focus on. I just thought it would be a cool story.