I don't doubt that sidehack can design a very efficient miner that "home/hobby miners" can use with their existing electrical and cooling infrastructure. I have one of his "green heatsink" Compac miners toiling away beside my computer adding insignificantly to the global hash rate.
My gut feeling with respect to the availability of chips of any generation is that the producers are relatively small and have excess demand from far larger existing customers for this current generation of chips, and so they have chosen to focus on the biggest bang for the BTC/USD/RMB/EUR/GBP or whatever currency you choose. It's a business decision. Additionally the mining machine producers can only get so many chips/wafers from the foundries that they use. Those foundries are making priority calls, too.
At the end of the day the home/hobby miner is pretty much the lowest priority for the mining ASIC companies. As long as there are huge commercial farms with hundreds of PH looking to upgrade, and/or investors with deep pockets looking to buy hundreds of PH in one go to build a new farm, the hobby miner will be relegated to the dust bin.
edit added: That said, if sidehack can get chips and produce an efficient home/hobby miner I'd definitely be interested in buying one or more.
The above is my stench.
Nice one. I typically use, "Opinions are like noses. Everyone has one and you can't pick mine."
Cheers,
- zed