I guess it's essay time.
I think the title of this thread is a commonly held opinion, but the reasons for holding it are at first obscure. After all, in Matrix:Reloaded, the audience is pummeled with even more awesome fighting, stunts and sci-fi effects, more bullet-time and bullet-stopping, more powerful agents (although they are mostly duplicates of one agent), more Trinity, and more mysterious beings (i.e., programs) such as the Merovingian and his servants.
But we are also given more Zion. In the first movie, we are not given much reason to care about Zion, just enough to make Zion's continuing existence a MacGuffin, a 'Maltese Falcon' as it were. The real conflict was not Zion vs. the Machines, but (externally) Neo vs. the agents; and, on a internal level, Neo vs. believing in himself and his own power, believing in love, and no longer believing in the matrix itself which is represented in the movie as being nothing more than green script crawling down a computer screen black background.
In Matrix:Reloaded, using Zion as a MacGuffin would have been pointless because Neo has attained his goal. So we are given more scenes in the real world, more scenes involving Zion and its collective struggle, represented by wet people dancing and something to do with orphans or whatever. SAVE ZION. Save the whales. Whatever. The conflicts are all externalized, there is nothing left to move the audience internally except for a love story and some well-done, intense action sequences many of which have been replicated in other action movies containing fight scenes.
Still, the Matrix:Reloaded possesses some meaningful symbolism, especially in contrast to that gory ultra-violent blood-fest called Kill Bill. There isn't a lot of bleeding in Matrix:Reloaded, but when it does happen it has meaning. When Neo is cut on the hand by the blade, all fighting comes to an abrupt halt. Then, when a minuscule drop of blood drips down from his hand, this is considered phenomenal because it means Neo is still human, thus giving the Merovingian a little hope that Neo can be defeated. This also perhaps gives the audience a little hope that Matrix:Reloaded has some deeper meaning to it than those benefits mentioned above. But it was not to be.