To be more accurate it’s dated back to when these were first introduced. If i correctly recall @Jainus was the one naming the Event Points like something he related to his experience as a parent during the times his little ones got sick. It’s all documented somewhere in the forums. 
A small correction: He didn’t called those Snotstones right away, but Snotgems. Maybe the term just kept changing over time. And i’m pretty sure that at some point he mentioned his fatherhood experinces when naming it, or maybe it was an unrelated topic by the time. I found his post: 2.2 Patch Notes - #203 by Jainus