I live in Columbia, and after this and the protests last year, I can tell you this is very much a side effect of the demographics of this part of Missouri.
This city has roughly 30,000 students out of a population of about 100,000. A vast majority of those enrolled are not from here, they come from all over the world. However, the city is over 80% white, and let's not sugarcoat it, there's an ugly history of racism in the state, period.
Those facts being what they are, I can understand everything in this story, and why it happened. I don't condone it, but I also don't condemn it. A lot of minorities feel like outsiders here (most of the student minorities actually are outsiders), but it's important to acknowledge that Columbia is a central Missouri enclave of a liberal bent surrounded by super conservative rural counties. The people who reside here, especially the faculty who work at the University and other colleges here, do so PRECISELY because it's not as conservative. So yeah, it feels awful when you're lumped into a historical and cultural shitpile of the last century by youth who probably won't give our fair city a second thought when they graduate and leave.
It makes white people here feel terrible, we know it's a terrible look, but the simple reality is that sometimes there's just no convincing some folks with an axe to grind that you care and are on their side, especially when a mostly white city is brow beaten for showing up to grieve for a predominantly Hispanic community. If people didn't care, they wouldn't have shown up.
I don't think this undergrad is wrong for having these views, and for discussing them publicly, but she was grandstanding at a vigil, and that only undercuts the legitimacy of her arguments. There are other times and places available to address them.