What am I missing about the Plasma Pistol?

Currently playing Bulwark and picked the Plasma as my sidearm, which seems to be the general choice, from what I've read. And while I certainly appreciate the utility of charged shots for interrupts and splash damage; I'm not sure if I'm missing something about the regular shots. They seem rather weak. Like playing Substantial with an artificer Plasma, it takes 4 or 5 shots to kill a Hormagaunt.

Is that just how it is or is it user error? Appreciate any input or tips you guys have, in that regard :)