Because tons of children are dying from preventable diseases like measles…

Bullshit. People used to have their kids play together if the measles started going around so their kids could get it over with. You don't do that with a deadly disease.

A 1962 issue of Parents’ Magazine & Better Homemaking stated that, “Measles has always been accepted as part of the growing-up process, as much a part of childhood as stubbed toes and dirty hands.” In fact, some parents even organized measles parties. According to a 1960 article in the Los Angeles Times entitled “‘Measles Parties’ Put Spots on Tots,” this was a growing trend in Canada, where parents wanted their children to come down with the disease before adulthood. quoted from http://www.huffingtonpost.com/jonathan-d-moreno/will-measles-parties-retu_b_14479732.html

They don't want people having measles parties again because it would expose the lie that measles is deadly.

"tons" of people are dying from measles? Stats or it's a lie.

~ from a measles survivor from the measles party era