Another thing about No Sense of Humour Sims is that when their Fun need is maxed out, it lasts much longer than other Sims. A normal Sim's elated moodlet lasts - what, 8 hours, I think - and a No Sense of Humour Sim's elated moodlet lasts for 15 hours. Which means they need less maintenance when they're doing activities that deplete Fun. I'm currently playing a writer with No Sense of Humour and he's always elated, even though he spends most of his day writing. So No Sense of Humour can be good in some circumstances. You just have to keep them from boring other people to death, if you don't want them to lose friends.