You can do more than spam one dungeon continuously. The design of it being Lore is to let people play the game as they normally would and accumulate the Lore to buy the items. It wasn't intended to be done in a day by people finding the quickest dungeon and spamming it over and over. While they could of added different options for it, it's not so much a flawed system, as it is flawed mindsets of "must have now".