The excessive restrictions on cooking pork didn’t come out of nowhere. In decades past, pork was intrinsically less safe than other meats because of muscle infiltration by Trichinella and surface contamination from fecal-borne pathogens like Salmonella and Clostridium perfringens. As a result, people learned to tolerate overcooked pork, and farms raised pigs with increasing amounts of fat—far more fat than is typical in the wild ancestors of pigs such as wild boar. The extra fat helped to keep the meat moist when it was overcooked.
Since then, research has sharpened our understanding of pork-associated pathogens, and producers have vastly reduced the risk of contamination through preventive practices on the farm and in meat-processing facilities. Eventually the FDA relaxed the cooking requirements for pork; they are now no different than those for other meats. The irony is that few people noticed—culinary professionals and cookbook authors included. ...
Clearly, cultural and political factors impinge on decisions about food safety. If you doubt that, note the contrast between the standards applied to pork and those applied to beef. Many people love rare steak or raw beef served as carpaccio or steak tartare, and in the United States alone, millions of people safely eat beef products, whether raw, rare, or well-done.
--Nathan Myhrvold, Chris Young, and Maxime Bilet, Modernist Cuisine: The Art and Science of Cooking, on why I feel OK today after eating medium rare pork in Santiago. HT: Marginal Revolution