Apologies if it was perceived this way. But I don't see how my comment link non-atheists with Holocaust deniers? My point is: Some people are going to believe things which are wrong (from your perspective) and that can happen at large scales. There are extremes (like flat earth) or socially-emotionally driven (like religious believes).

I say give anyone the freedom to have any opinion as long as he doesn't incite violence or act on it.

For antivax it is really a complicated one. I don't have a problem with antivax advocates but I have a problem with parents that don't vaccinate their kids. And I think the government should act on the best interest of its minor citizens.