Imagine that ASIC manufacturers have found a parallel application for their devices, which is in demand by millions of consumers, and not by tens of thousands of miners.
The idea would have gained more interest.
There is nothing to imagine. Has someone forgotten what the 'AS' part of ASIC stands for?
Application
Specific. The chips can only do 1 thing - process hashes.
Now perhaps someone can come up with a different purpose other than validation that the results of matching a hash can be used for but the mfgrs have nothing to do with that part of the equation.