Inoculation campaigns that protect children and adults from dangerous diseases rely on a delicate web of state and federal laws and programs. If senior officials cast doubt on vaccine safety, the whole system might collapse, especially in red states.
What people choose to do with their own lives is kinda up to them --- the proverbial self-inflicted gunshot wound is, well, self-inflicted.
It's the children, elderly, immunocompromised, etc. getting caught in the crossfire that's scary. (Not to mention the new breeding grounds for nasty variants.)