I agree that in general people are better off sticking with good quality unprocessed foods, but in Dr. Atkins' defense many people do seem to be able to eat those bars and keep on losing. Keep in mind that people who aren't having a problem generally don't tend to make posts about it so we only hear from those (usually) who are having a problem with the bars and that makes it look like everyone has a problem with them when in fact, not that many (statistically) do.
The bars do have quite a bit of vitamins and minerals added so they aren't totally empty calories and when the alternative is to eat a candy bar, I'd say that the Atkins bars would be a better choice but if it was available, I'd more likely head for a protein snack instead.
I had an Atkins catalogue handy, so I checked and the bars are listed as appropriate for the induction phase, but my general advice to anyone who asks is to avoid them until the ongoing weight loss phase and if they seem to stall weight loss, to not eat them at all until maintainance. For some, even the taste of something sweet (this includes artificial sweeteners like Splenda and Aspartame too as well as the sugar-free chocolates and jello) can provoke an insulin response and cravings.
The products are out there because there is a market for them, but as with any product on the market the general warnings, "let the buyer beware" and "YMMV" always apply.