Sure, could be. Who knows why they didn't laugh. Maybe they had just had a big fight and were trying to make nice. Maybe they were on their way to a funeral. Maybe the joker had been staring uncomfortably at them before telling the joke. Maybe they just suck as humans, who can say. I guess my point is that it's hard to know why someone doesn't laugh at a joke, and jumping to "those people just suck" as a first resort is a thing that people do when they don't want to think critically about how they are received by other people.