I had actually read the same post and was thinking along similar lines to you. Basically an app that takes in steem and pays in fiat to any business.

https://steemit.com/busy/@niallon11/steemtransfer-theoretical-concept

This is the answer that i gave to the same post. The main problem that i see right now is how tough it is to turn fiat to steem and steem to fiat. If we can make a simple solution to this i really feel that it will make all the difference to mass adoption. The majority of people will never get involved while everything is so complicated to work through so until we can make it a straight line it's going to stay a niche endevour.