uh no. You are right that herd immunity would be lost in the charter school. BUT, herd immunity requires about 95-98% immunity. Those who have medical reasons to not take vaccines are about 1-2%. That leaves only 1-2% to play with. Sadly, the amount of ppl that have gone off the deep end is INSANE and therefore we only have less than 90% immune. So, it is not fair to those that have medical issues or those that took the vaccines, but it did not take, to mix in those who CHOOSE to not take vaccines.
If you want your child to have that herd immunity, then they should be taking the vaccine. To insist that your chlid NOT take vaccines because you do not think that they work, or that they will impact your child, or that you have religious reasons, and then want to expose others is just beyond belief and shows that YOU are the one wanting to punish others.
By offering up an alternative of a separate school for those that choose to not vaccinate, it allows ppl to make clear choices.