Well of course it can! Just pick up a good western or two. However, when you read certain books and media, you usually can predict that racism will be involved. So, a western based on a black cowboy would probably have some rather racist statements in the story.
Howeve, this is fallout, not that western or other book. It's where ghouls are where the prejudices is pointed at. Their fictional and represent no real race.
However, it wouldn't be cool to pick up fallout 4 and hear a racist comment splurted at you. Fallout is a post apocataptic roleplay game. Human Racism hasn't been in it since the first, and it should stay that way. If someone wants to be exposed to racism, there are plenty of other media out there.
I get your point, I really do. And obviously I've read great books with racism in them and the like. However, I feel fallout really doesn't need to go there since there is so many other story telling elements out there. Plus, that comment that you should be attacked randomly by another person who hates your skin is pathetic. Just because I'm Asian a white/black/blue
guy should spawn out in the waste and attack me for a rather weak reason? (we all know Bethesda such at back stories.)
Speaking of which, they'd probably implant racism in fallout so poorly and stupid, that you'd see my point instantly. Story telling isn't really Bethesda best Attribute. Obsidian, however, has GREaT writing, and great writing without any human racism involves! Tadah!!!