The thing is many humans did not survive to get us here. I think this is a key point a lot of the antivax crowd doesn't see.
I'm not really sure what your point is. We shouldn't try to help those with weaker immune systems survive? How far should we take this? Should we as a society not make an effort to help the physically disabled, the old, the blind, etc. survive? Looking to the wild, basically no members of those groups survive. Is that what we should aim for?