For the same reason Gallia only has Imp. Cargo Scanners: the Devs missed something.
A way a lone a last a loved a long the riverrun, past Eve and Adam's, from swerve of shore to bend of bay,
brings us by a commodius vicus of recirculation back to Howth Castle and Environs.
Because future releases may see ships which can use them?
For now, we take comfort in the warm flow of Gallia's insanely poor debs, Council with empathy to the Maq, bomber patrols, level 18 NPCs, restricted trade rights and shaky claims to superior combat technology.