i think this thread brings up a good question. To some people, the Naruto anime ended almost two years ago. Those who waited for Shippuuden with baited breath were expecting something, and then the studio went out and declared that Shippuuden would be a brand new series, if only for marketing gimmick effect.
So then, it's not unfair for us to be judging Shippuuden's worth so far as it's own series. Personally, it takes a great deal of things for granted. The missing backstory is not the biggest hole, to me it's the fact that Shippuuden simply assumes you know all about chakra, jutsu and the general makeup of the world. In a way, this starkly contradicts the idea of making this a brand new series...
Also, a place to vent about Shippuuden, which I can rather safely say has disappointed more than it has impressed so far, is somewhat due considering the collective sufferring through filler hell and the general anticipation, just to be brought this.