One of the things I’ve noticed about people like Paul Offit and David Gorski (aka Orac) is that they like to avoid debate with people who disagree with them on vaccines. One of their favorite ways of doing this is to try and delegitimize their adversaries through continual ad hominem attacks or simply by saying they’re not qualified to debate the issue. The goal is to make it difficult for them to be heard respectfully. Donald Trump is another character who commonly uses this tactic. Since they do not have sufficient command of the debate material themselves, people like Offit, Gorski and Trump usually opt against substance and go straight to the personal. It’s a kind of survival mode for them.
Survival mode for the unprepared