Unless I'm mistaken, there is an entire network of super awesome computers performing calculations en masse for the sole purpose of slowing the system down. That makes sense, except, there is no reason the calculations need be meaningless. Why aren't the crypto-hash-puzzles something more productive; searching for near earth objects, fiddling with the human genome project or patrolling the sky's for ET, curing cancer etc. Surely the miners could be earning their coin for something more productive than wasting computer clock ticks? Smart People, you could make this happen, right?
I understand what you are trying to express. You are saying that we can use this calculation to solve something meaningful that would be beneficial to the society, something like finding large prime number, or that "special" number that can be used for enhancing cryptography securities, encryption and so on. They may not be a way now but people may come up with something in the future.