1.0 have such things in the dungeon. you had extra boss extra items for gear and such but they were in out of the way areas and most people hate the leg work to get there, so when the revamped to 2.0 such things went away. after all many people explore every room in The Thousand Maws of Toto-Rak. that place in 1.0 had like 5 or 6 bosses in it