People think of many things.

Some think that the side effects outweigh the benefit for certain vaccines, which in certain cases MAY be fair. That'd be a choice that would be made for individual vaccines based on the history of side effects on your children. This is the portion that I understand.

There are some people that think that the people that are making and telling people to get vaccines are in this major effort to take over the world, that vaccines cause autism, and so on and so forth --> These are the people that should be ostracized by society.