IMO the teaching of tables is not really needed anymore.
1. Dive computers do everything needed and they do it better.
2. Dive computers are reliable - DAN has statistics to prove it.
3. A few years after their cert. classes, most people can't remember how to use the dive tables.
4. Tables are not a good backup strategy because people don't have the needed information or knowledge to make the switch from a computer to tables.
5. Dive tables don't teach you any more about decompression theory than a computer does, they merely present the information in a different - and less flexible - format.