I've now had this conversation in multiple threads, so I think it's time to address it directly. I'll try to do this with an analogy, to reduce the tensions a bit, and hopefully make it clear.

Here are the facts:

1. People in New England (Yankees) tend to have higher rates of seasonal influenza and other upper respiratory tract infections than other populations.
2. Hygiene, especially hand washing, can reduce transmission rates of these illnesses.

Here's the timeline of the dispute:

1. In the early 1990's, Marles Curray writes a book about infectious disease and epidemiology. Most of the book is focused in the life cycle of viruses and how they're studied, and different public health interventions to reduce infection. All of this is perfectly rigorous, but there's also a chapter about hygiene specifically, and in it, Curray draws what some believe to be a spurious correlation between the link between hygiene and infection rates in the northeast. He doesn't say this directly, but some readers, sensitive to a long history of prejudice that Yankees are filthy, read into it.
2. Contemporary coverage of the book highlights this controversial chapter, and Curray fans the flames by never quite denying the link. Over the next 25 years, he has a successful career as a conservative thinker, lobbying for defunding food safety regulations in New England on the premise that their lower cleanliness renders these programs ineffective.
3. Curray gives a talk at a small college in New England, and is shouted down and physically assaulted. Many on the left decry the violence, though some on the fringes think this is an appropriate response to yankeeist hate speech. The right promotes this as SJW excess, and most characterize the left's objection as denying the truth that hygiene affects transmission rates of illness.
4. Ham Sarris, having previously ignored Curray on the basis of his reputation as a yankeeist, but caring about intellectual honesty, invites him on the podcast. He introduces Curray as someone that's been vilified for speaking the truth about public health and the importance of hygiene. Most of the podcast is about viruses and public health. But when Ham asks why anyone should care, Curray talks about how this should affect how we think about food safety programs in New England.
5. The epidemiologist Richard Tisben and colleages write a piece in Populi, accusing Curray of peddling junk science, and says Ham Sarris fell for it. It argues that the evidence does not support the notion that New Englanders have worse hygiene, and point out the history of yankeeist stereotypes that linking hygiene to increased infection has been used to promote. This piece includes the line, "We hope we have made it clear that a realistic acceptance of the facts about virology and hygiene, tempered with an appreciation of the complexities and gaps in evidence and interpretation, does not commit the thoughtful scholar to Currayism in either its right-leaning mainstream version or its more toxically Yankeeist forms"
6. Ham believes Tisben et al are saying he's peddling junk science and calling him yankeeist, and doubles down on the assertion that Curray is right on the science. "It would be a miracle if there were no differences in cleanliness between populations. And all of these SJWs are denying the fact that hygiene affects the spread of infectious disease."

Here's the problem:

1. Ham Sarris thinks folks like Tisben and from the politically correct left are claiming that there's no link between hygiene and disease. This causes him to label them as on the fringe.
2. The reality is that no one is disputing this link. Nor are they disputing that populations might differ in hygiene. The actual objection is to the specific claim that the increased rate of infection in New England is the result of differences in hygiene. This could be true, but the evidence doesn't say one way or the other. And a history of yankeeist stereotyping should lead us to be cautious.
3. Sarris continue to claim that he was accused of being a yankeeist (he wasn't), and that his detractors are unwilling to admit that hygiene plays a role in infection rates.

I hope this helps, and maybe even provides a bit of levity. I'm sure some will dispute my interpretation of events, but I just wanted to end with a quote from renowned Harvard geneticist David Reich. This was the piece that Sam linked to as vindication for his position and that started the latest round of this dispute. In fact, it expresses precisely the same point with respect to race and IQ as Nisbett et. al., albeit with a different focus and without the name calling (emphasis mine):

Another high-profile example is James Watson, the scientist who in 1953 co-discovered the structure of DNA, and who was forced to retire as head of the Cold Spring Harbor Laboratories in 2007 after he stated in an interview — without any scientific evidence — that research has suggested that genetic factors contribute to lower intelligence in Africans than in Europeans.

...

What makes [these] statements so insidious is that they start with the accurate observation that many academics are implausibly denying the possibility of average genetic differences among human populations, and then end with a claim — backed by no evidence — that they know what those differences are and that they correspond to racist stereotypes.