to solve this hodl problem we need a new kind of service. A combination of payment and exchange service. with this service it should be possible to pay for something in bitcoin and also instantly exchange the same amount of fiat back to bitcoin - payhodl.com!
Trust me, when most of your wealth is tied up in bitcoins, you will spend them.
The flaw is thinking that people that get it will be holding very much fiat to spend. Maybe enough for a restaurant or groceries for the week but the big things like travel, large purchases, etc. are done with bitcoins.