My main one has to be grinding for the sake of grinding. If you come upon a story based boss I shouldn't have to backtrack a few tens of fights just so I can level up and beat said boss. WRPGs tend to eliminate grinding by giving a large amount of experience for side quests which I generally prefer (although this can also result in the flaw of over-used fetch quests). This is exacerbated when games add in lots of easy encounters just to buff up the content.