I think that a problem with generalized uses of "blockchain" to support some $USE_CASE is that you need a decentralized system to reward miners/stakers in order

I think that a problem with generalized uses of "blockchain" to support some $USE_CASE is that you need a decentralized system to reward miners/stakers in order for it to be worthwhile, so you end up reinventing a cryptocurrency with whatever $FEATURE tacked on. The best case of this is something like filecoin or namecoin. Two very old projects as well. To a lot of groups, inventing another redundant cryptocurrency is a feature not a bug. A lot of these companies (big ones like Ripple Labs come to mind) essentially want to use the excuse of "cryptocurrency" to release an unregulated funding coin that essentially acts as a security. Even as a cryptocurrency supporter, it is easy to see how this is detrimental to "real" cryptocurrency because is diluting the purpose of decentralized money with centralized funding tokens and nonsense. It's obvious that blockchains have little use outside of decentralized money due to their obvious inefficiencies.