I have never paid much attention to the Weston Price Foundation. They have spread what I feel is a lot of misinformation about soy, so I don't put a lot of faith in their claims. If they want to convince me I would like to see some real evidence of their claims.
Furthermore I think they are not taking in to account all the information. For example they are claiming that the glucosinolates are a goitrogen in humans. But we have to consider the effects of other compounds in the body such as enzymes and how they affect the glucosinolates and their byproducts. There is obviously more to the story than what they are claiming. For example a lot of people use maca to support the thyroid, yet maca also contains glucosinolates. I wonder how they would explain how this contradiction? Here is another link you may want to read;
One study showed no ill effects when volunteers ingested 40 mg goitrin/day in Brussels sprouts over a 4-week period. Another study showed inhibition of iodine uptake after administration of 50-200 mg of goitrin. Studies in Great Britain estimated an average intake of 76 mg glucosinolate per person per day, with a range of up to 200 mg per day. 2 Whether or how much the consumption of Brassica vegetables contributes to ill health in humans is unknown. The cause of endemic goiter in certain geographic regions may be the result of the interaction between iodine deficiency and certain food components, such as glucosinolates.1
Many nutritional studies have shown that dietary fruits and vegetables, including those in the Brassica group, have a protective effect against certain cancers. In animal studies, glucosinolates and their breakdown products have inhibited tumor formation, although this anti-carcinogenic effect depends on the study design, the type of cancer being studied, whether other dietary components are present, and the timing of the administration of the glucosinolate compound.6
In summary, glucosinolates are known to be goitrogenic in animals, but their role in inducing goiter in humans is less clear.They can be anti-carcinogenic and cancer-promoting, depending on the species and circumstances of administration.6 In general, dietary vegetables, including Brassica vegetables, are beneficial in cancer prevention."