Everyone (within reason now, obviously I'm not telling someone on their death bed to go do squats, although that would kick ass) should workout because it's objectively healthy for you.
But again, I don't usually phrase it like that because the fitness community is often obnoxious as hell and being condescending to the gen pop is a big turn-off to people.
Currently playing: Skyrim, Hearthstone
Training log: https://powpowpunishment.blogspot.com