A lot of smart folks just have enough other things to deal with in their life to allow them to make informed decisions on every single topic. At the same time, marketing machines use side-channels to put unhealthy choices at the front of their minds. I don't see a problem with countering that bias. It doesn't mean they are dumb.

Public health is also a big factor in society, even economically, so your argument below about vaccines does apply to healthy eating as well.