The truth is that there have been no long term studies done on the effects of consuming a low carb, moderate protein, high fat diet. We have examples of cultures that primarily eat fat and protein and thrive on them (see above for the specific peoples). Higher rates of disease have only shown up in these peoples when they started adopting a more Western type diet. For example, acne was virtually unknown among the Inuit (they didn't even have a word for it) until a more Western diet was introduced; ditto for heart disease and diabetes.

You can't use the induction phase of one particular low carb plan (and there are many other types of plans besides Atkins) as an example of the whole plan or all low carb plans. It's two weeks on a plan that lasts a lifetime; a mere blip on the radar screen. Even the induction phase of the Atkins plan doesn't cut all carbs. There are no low carb plans that I'm aware of that cut out ALL carbohydrates. If you know of one, please share it. Personally, I consider the ADA position that it's okay for diabetics to consume sugar as long as they cover it with more medication a bit extreme.

There are conditions for which drastically reducing carb intake and limiting the carbs that you do eat to those that are low glycemic has been shown to to be effective such as PCOS, Epilepsy, hypoglycemia, diabetes and insulin resistance (otherwise known as Syndrome X). More and more doctors are starting to recommend low carb plans for these conditions. One of my co-workers was just diagnosed with hypoglycemia. Her doctor's recommendation? No more than 50 grams of low glycemic carbs a day. Another of my co-workers was diagnosed with insulin resistance. Her doctor's recommendation (after consulting with his dietician)? No more than 40 grams of low glycemic carb a day.

Fat has not been shown to contribute to heart disease in the absence of a high carb diet, unless you want to start talking about hydrogentated or transfats which I'd like to point out that many low fat products contain along with high amounts of high fructose corn syrup. If you know of any study that has, please post it.

The link you gave to PCRM's site is an opinion, not a study.