Why would any company spend so much on R&D for the A3 knowing that it will flop?
I don't think they care too much about how successful the miner will be in terms of ROI. They turned $13M worth of miners in 20 minutes... and if they do the same for batch 2, 3, 4, 5 etc, that alone will probably be worth way more than what they spent on R&D.
More or less, exactly. They make an unimaginable amount of money per year by simply selling the miners, not even including whatever it is they're mining with, god knows how much money they make with their farms.