I would agree if this decision would only affect themselves. But vaccination against infectious diseases works best if the majority is vaccinated. Then you can actually stop it from spreading. Which is important for all those that cannot be vaccinated for legitimate health reasons. Some vaccines are dangerous for specific subsets of the population. And usually it’s the same subset that would be most affected by an actual infection of the diseases we vaccinate against. Small children, pregnant people, any immunocompromised people… Vaccinating is an act of solidarity and community.