Well it could make sense since one BFL asic chip for example costs 70$per piece if for example I could combine 10 audio chip at 7$each doing half or 1/3 the MH/s rate of a single bfl asic then It would be profitable buying like 1000 chips (which will lower the per chip price) spending a few more K for the board design and you have almost instantly mh power whenever you want to upgrade you have just to make a new order that will arrive in a mater of days maybe weeks at worse.. no 6-9+ waiting time.
So why not use popcorn instead of an airplane since popcorn is so much cheaper? Because if you want to fly across the country, you want something that was designed to fly across the country.