Why is it so hard to accept that Au Ra have no more connection to Dragons and void sent than Miqo'te do to Couruls?
Let's not forget that Dragons were concerned to reproduce asexually and Voidsent consume Aether to the point of killing and devouring different beings in order to consume THEIR Aether.
TL:dr Dragons don't need mates and Voidsent would sooner eat you than look at you. And if Au Ra are half Dragon half man, than Miqo'te are the decendents of Myracidian Cat [Kupo]ers.