Just my 2 cents speculation
the point is not to compete with asics... as we have seen recently any coin with a large marketcap is going to have an asic implemented after some time. the point is that an asic will only ever work for that algorithm. an fpga can do many many kinds of algorithms, you just need to program it. i assume the people who know fpga's can look at a coins algorithm and whip up a miner similar to how people cook up gpu miners for cpu only coins. your gravy would be any algo that you could implement efficiently onto an fpga that no one is going to make an asic for.
Yes, I get the point.
But if your FPGA cost $2000 USD and can do 500 hashrate while the asic cost 400 USD and can do the same 500 hashrate, u are still screwed.
U will switch to other coins but so will all the FPGAs and GPUs. Those other coins that are not yet touched by asics will then have their mining difficulty skyrocket due to all the FPGAs and GPUs going there.
Basically, u will lose on a cost per MH/TH basis by too much even if u can match the asics efficiency. And looking at the speed in which asics appear on new coins these days, I dont see how that can work. This looks pretty sucidal.
Just my 2 cents speculation