Primarily, the show introduces things that it fails to properly utilise, which is the main cause of its failing. The main trio of girls - Tamako, Kanna, and Midori - have some immediate chemistry and charm together, but are rarely actually properly used outside of a few moments, there are two love plots (one between Midori and Tamako, and one between Tamako and Mochi) which both remain underdeveloped, and one of them is just swept under the rug as well.
If the show could have focused on its strengths, instead of being mostly directionless, it could have been quite enjoyable in its own right, though always in the shadow of K-ON! unfortunately.
