Proof-of-work having secondary commercial utility is troublesome because it can result in a situation where the secondary utility becomes more valuable than the former, in which case the currency is liable to collapse.
I tend to think that proof-of-work must be inherently useless in order for it to function for this reason - otherwise, it's not 'work'.
I tend to think that proof-of-work must be inherently useless in order for it to function for this reason - otherwise, it's not 'work'.