How can you benefit from the ability to make another sim tense or sad?

I was thinking a similar thing when I learned there is an oil you can put in a hot tub that will make Sims uncomfortable. I guess trolling is really what these kinds of things are good for, as the emotions don't really change much beyond a few hours of a Sim's emotional state. But like you, I don't find it fun to do those kinds of things because again, the moodlets don't really matter.