Is green electricity suppose to be nonviable now? If you can accept that green electricity, which will be the dominate source of unexpected cost, is going to be very cheap, then anything predominately made from it will also be very cheap.
This is a repeat of the anti-wind and solar attacks because it is the same general principle. Basically an appeal to the unknown that the new green technology couldn't possibly be cheap, despite plenty of evidence that cost is dropping or that there is no expensive supply chain.
How much will each kWh generated from synthetic fuels cost?