It's also good to remember that the tech world is built on all sorts of 'objectively obsolete' technologies.
If there's a shift, it can quickly turn into a flood, since much of the value of bitcoin is based on speculation, rather than more robust demand from use as a payment vehicle.
Hardware, and electricity investment is not static for miner upkeep. A fun feature of most cryptocoins is the ever increasing demand for hashing power, forcing miners to constantly consider the value of their real costs versus the real value of the protocol they apply their equipment to.
So by design, the network effect of cryptocoin miners will flock to whatever the current best design is on any given day.