JP trip was never meant for all of them to get together though, it started out as Elira inviting Reimu and Petra to hang out together, the next day everyone started to invite themselves in, and it was also when they got hit with news about cancellation of event. Before that they considered to go as three of them anyway and spend time together declining everyone asking to join. They just felt bad for the rest and everyone was feeling down so it got kind of sacrificed in favor of group meeting instead. Reimu talked about the whole process in her return stream
At 1hr 58min and 2hrs 59mins, she did go on a tangent for an hour in between, the first part is just one sentence saying who was supposed to go. I don't think everyone hates each other, but I also don't think everyone likes each other, and random trip that was repurposed after really bad news is not exactly indicative of anything.