Hypothyroidism is not rare, first of all. You even said in one of your epic threads a few months back that the reason many people are likely suffering from worse health after switching to primal is that the massive amount of sugar and salt they were eating on their SAD was keeping their thyroid afloat, and with those gone their thyroid is tanking.
The estimates vary, but approximately 10 million Americans have this common medical condition. In fact, as many as 10% of women may have some degree of thyroid hormone deficiency. Hypothyroidism is more common than you would believe, and millions of people are currently hypothyroid and don't know it.
Also, this is an excerpt from your opening post on 'Sugar Isn't the Problem':
"...These things, along with chronic stress from every day life, leave cortisol levels constantly elevated. Cortisol is the stress hormone, and when it is elevated, it is destroying your body. This will make you hold onto fat, it will make your hair fall out, it will ruin your mood and destroy your sex drive."
If caloric underreporting was the REAL reason that 99% of people aren't losing weight, why would cortisol matter? I don't doubt that many people DO underreport, but it's disingenuous to claim one minute that people are fat because of stress-induced cortisol, and the next minute take it back and claim it's just about underreporting calories.