Your analogy doesn't include some important details for the subject. In the game, crewmates and imposters are on different teams and only one of them can win. It's not "wrong" for an imposter to kill a crewmate because that's how they play. All players support imposters killing crewmates because it's what they signed up for. But in real life, we are on the same team. We are all crewmates doing our tasks, although I guess we have the option to kill each other. Acting as if someone doing their tasks near you wants to kill you is then a more meaningful personal judgement rather than just the impersonal scrutiny expected in a social deduction game.
More importantly, it's relevant that this is one group of people making a judgement about another group of people based on group membership. So it would be like green crewmates assuming a red crewmate is an imposter on the basis of them being red, not any suspicious activity they have noticed. If crewmates had equal innate suspicion towards each other regardless of color (as should happen in the game) then there is no issue.