Another interesting application of blockchains could be to the yelp/foursquare/tripadvisor/opentable/dining-rewards/loyality space. One protocol to handle menus, reviews, and reward points, instead of a separate incompatible reward app and shitty non mobile website for each damn restaurant. Another, and different component of trust in this ecosystem would be verification of authenticity vs spam.
On one hand: of course, yes, that would be awesome! On the other, the coordination problem vastly overwhelms the technical problem i.e. getting a large group of competitive companies aligned around a single standard is impossible, insert link to xkcd 'competing standards' comic here, etc. I get that blockchain 'solves the trust problem' but the problem of distrust between those competitive actors is not related to former.
OTOOH: if the hype around blockchain is what we need to get those gaggles of competitors aligned around something...
the world standardized around http/smtp. I dont think a standardized restaurant-menu-trust-loyality-payment chain is impossible. Look how long it took email to take off (and then got replaced by facebook.)
Its much more likely for a yelp/foursquare to gobble up the market, but I'd prefer a decentralized protocol for distributing menus...
And to criticize your criticism, standard menu metadata + loyality + reviews is not a complicated process, its just not an angle thats really been attacked before. I dont know of a menu database that is intended to feed third party clients like yelp/foursquare/allmenus. All the menu hosts want to be the end user client. My idea is more about separating the database from the client, and sharing a database between a couple companies. For something like this to happen, all you would need is yelp and foursquare (tripadvisor, opentable, zagat, urbanspoon, zomato) to create a consortium and invite a couple other big players. Its not about the restaurants self organizing.