Catching is traditionally a weak position offensively. This past year was more the norm than some of the prior years. There's always going to be some guys that do well, and other times, some that do really well.
Not that Yahoo stats are the 'be-all and end-all' of stats, but they are a decent barometer. The top rated catcher this past year (Victor Martinez) was rated #160 overall in terms of offense output at the end of the year.