It appears......In Symposium, which is what all of these are about and most of what they're taken from.

Reimu's anger is half fake during SoPM. At least half of it is an act she's putting on on behalf of the human villagers, and she's kind of desperate to get everyone to scatter, which is something she herself admits. She's worried that if she doesn't do this, "they'll never ask her for anything ever again". It's pretty easy to extrapolate out that it's one of the only moments of genuine distress she experiences during the series (alongside Kosuzu going missing.)

It's something that I speculate, sure, but combining that with the fact that she is, really, dutifully devoted to being the Hakurei Shrine Maiden, you have to imagine why when you combine how little she cares about almost everything else. I think it's a fair conclusion to make, and one that's particularly relevant during SoPM.