Sure, someone like Bitmain couldn't control the distribution of FPGA devices in the same way they can control the distribution of their own ASICS, but they could dominate mining in the FPGA world simply thru economies of scale. What does it matter if 10000 home miners are out there with a few FPGAs when Bitmain can afford to have enormous industrial scale mining operations in multiple countries, and because of their scale at much lower cost ?

The implicit argument by FPGA proponents that they contribute to decentralization and are (therefore) implicitly good (TM) is really just a selling point used on their behalf to promote their own interests.

I like the idea of FPGA mining as much as the next girl, its geeky and fun, but seriously its not going to save the blockchain from the likes of big business.