There are undoubtedly some development tendencies that will push mining more towards bigger installations (this is nothing new).
That doesn´t mean you cant profit from this development, but your home-miner at 0.15$/kWh is indeed unlikely to ROI any time soon ever again.
Bigger commercial buildings with 100TH+ mining power already account for more than 50% of the network.
FTFY.
What could be possible is a million usb miners spread far and wide to maintain the vision of the public miner.