Lack of Nexus 4 bumpers - why?

There clearly is a supply / demand issue with the Nexus 4. But you would think at the very least that there would be some far eastern fab unit churning out millions of the Nexus 4 bumpers in wonderful colours. But no. Not even enough black ones. And to my dismay, there aren't even knock offs on ebay.

So why? Why would this "quick win" for both LG and Google not ensure the complete accessory ecosystem was in place?