You only find recipes relevant to a craft you've taken up - and once that maxes it goes random. For instance, A Smither only finds smithing recipes. When he finds them all he starts finding random recipes. A tinkerer and smither finds either or then randoms. Someone without a craft finds randoms. I just find crafts nerfed hard enough given you not only have to find the recipes of the scant few good weapons, but they come out unenchanted. I hit floor 7 and still haven't found the Flail of Pleiades recipes. :|