With so many important things alive and in dire need of work and attention, why should we give that old dusty relic in a corner of space where so many others have filed up the void any prime attention.
Let those Sith gather dust for another couple of millennium. We have much to do before we even have to breathe one thought to them.
Development of the Reapers of Sirius faction and assets is currently on hold while more pressing tasks are being worked on (read: almost everything else).