Critics quote “I don’t like sand” so often because it is simply the tip of the iceberg of the entire wooden Anakin dialogue.
As you said, there are so many sequences in this movie but most of the stuff is dramaturgic non-effective because Lucas’ script (along with Jonathan Hales little input) is not well written.
The movies of the Original Trilogy are fun space adventures with likeable characters. The movies of the Prequel Trilogy are melodramatic costume dramas with flat underdeveloped characters.
It’s not the amount of the special effects that drags AOTC down - it’s Lucas’ script & directing.