The developers they've replicated are too stiff and un-weildy - so far. The developer replication program has, therefore, been suspended. (The world has enough Microsoft executives.)
The reprap is a sybiotic organism, it leverages the human desire to build cool stuff cheaply to help it reproduce much like insects with flowering plants. However, if the symbiotic approach proves evolutionarily unfavorable, a parasitic or even predatory approach may be considered. Hence the need for developers.