I agree this could be a problem, but that's not what cultural fit is supposed to mean in this context. Working culture is just how things are conducted at work

I agree this could be a problem, but that's not what cultural fit is supposed to mean in this context. Working culture is just how things are conducted at work, it has nothing to do with personal views per se. If your culture is one where everybody makes homophobic jokes all the time then it could be a problem, but under most professional cultures (certainly HR in any corporation would lay down the law on this) personal views should not be part and parcel of the culture.