the basic SMG is decent as an alternative to the Shiny Niner and other basic civilian-tier pistols. it fills the same niche for both fast scouts, reaction spam, and meleetroop sidearms.
the spiked SMG and holo-spiked SMG are utility sidearms for heavy melee troops, for example paired with a bardiche or spear. in this role it's a firespreader or armorstripper as well as a melee capture tool. so despite the mediocre performance all around it still has good utility for its inventory space.
also, technobarb commendation