dba_afish said:
It doesn't have anything to do with the spice. I believe that it's meant to bring to mind the medieval weapon, implying it's similarly effective for defending oneself.

That's what I was thinking at first, but that seemed like too simple of an answer.

Grab-n-Stash said:
That's what I was thinking at first, but that seemed like too simple of an answer.

"Mace" spray also does count as a pepper spray, per its current primary ingredient -- although it seems its primary ingredient used to be tear gas.