Well, nobody I know uses hash tables without periodically "rebalancing" them either.
Where I went to school, we were taught not to compare the worst case behavior of one structure to the average of another. We were also taught not to confuse binary trees with red-black trees.
I guess your school sucked. Red-black trees ARE binary search trees. Also: the worst case behavior of a hash table is in fact worse than that of a balanced (red-black tree, b-tree, avl-tree) search tree.
Where I went to school, we were taught not to compare the worst case behavior of one structure to the average of another. We were also taught not to confuse binary trees with red-black trees.