The author gives several reasons for their decision. I love my Lodge cast iron pan, but I also agree with the reasons that the author gives when choosing to not recommend them for "most" people.
One of their reasons was that they can't find any evidence regarding the long term effects of eating out of seasoned cast iron pans. That rubbed me the wrong way, because it seems to be trying to suggest that, until proven otherwise, the absence of evidence suggests that there may be a problem.
Well… yeah? We know that smoking oil is carcinogenic, and it forms this weird polymer layer when a pan is seasoned. Would not be surprised if further research shows that Teflon is actually safer.