In a civilization where there is constant peril, men are expected to die for the race while women ensure there is a race. Anyone who isn't of a part of that race is different and has less reasons to be your friend, and therefore should not be trusted without proving trustworthy. That's how things work in a less than ideal world, such as mine. However, distrust and expectation does not translate into "Kill the [X], race war now" and "get back to the kitchen, wench." (Though those people always exist) Outsiders can be friends and even allies instead of enemies, women can do their part in war or government too, if they desire it. But that does not change the fact when it's time for peril, there's usually someone who isn't of your tribe on the other side, and that a mother is more valuable to the civilization in the long run than another soldier for the meatgrinder.

People get antsy about racism and sexism, preferring to dodge it rather than acknowledge that not everything will be perfect and that unfair and/or preemptive judgments will be made about others. Maybe because Americans (and many of us here on the internet are Americans) see their past of racism and sexism (especially the former) so shamefully and want to avoid any memory of it at any cost, because people who were wronged by it are still alive today.

But in the end, I have an easier believing that these biases and expectations exist than believing they vanished wholly. Even if they're transferred to more abstract notions like national, religious, political, or whatever affiliations. Someone will surely say "It's fantasy, it doesn't have to be realistic," but Earth's history played out the way it did for a reason. People are creatures of habit, and it takes some big changes to break those habits. I suppose it's a good thing this is fantasy then, there's plenty of room for big changes. But without something that big to make a behavior change, I'm not gonna believe that people won't be judgmental pricks about race, sex, religion, whatever.