The profit margins for mining may be higher with ASICs but FPGA Bitcoin mining may still be worth it. Would really love to hear a more technical rationale for why public opinion is so against it, I personally think of it is as a viable option if you have multiple high end FPGA boards.
You underestimate the efficiency of the ASICs that we have. My USB ASIC has a higher hashrate than FPGAs while being more efficient and potentially cheaper. FPGA is okay if ASIC isn't mature already. That isn't the case for Bitcoin, anyone would prefer using an ASIC over FPGA for SHA256D unless they don't care about profits.