Ive yet to have someone explain to me why they think FPGAs are so bad but GPUs are so good.
Thats a red herring. Who is making that argument ?
The developers who have forked explicitly over their algorithms being listed in this thread.
The economies of scale argument also applies to GPU based mining. For example, with modest capital I could easily build a host system supporting up to 128 GPUs (since no one uses the PCIe for anything other than making them boot and comm that is lower than serial speed), supporting individually resetting and reinitializing them and all the benefits of smaller hosts, but at 5% of system cost instead of as much as 30%, and also provide power savings. The difference is Bitmain doesnt represent enough demand to independently control the FPGA market, and the companies in that market are not going to sacrifice decades of high margin business for a short term cash play.
There is no down side for TSMC or commodity memory manufacturers to take big money for cheap part orders from Bitmain or any large player.. There is a downside for Xilinx/Intel flooding the market with cheap FPGAs. Similarly you dont see NVIDIA and AMD letting Bitmain build custom mining GPUs with their chips at cheap prices. Companies with massive R&D into their chip products want to very carefully maintain control over markets to keep the balance between volume and margin exactly where it is most profitable.