I grew up before chicken pox vaccinations were wide spread. People who came down with it were quarantined, not encouraged to run around and give it to everyone to establish immunity. I did not get the disease, and although I think I got vaccinated later, I am glad that the chances of my DS bringing it home from preschool are lower, now that I'm pregnant..
I am not sure what your point is? (said nicely - no snark)
I have had CP, 2 of my 3 children had CP (the 16 and 13 year old). In all cases we stayed home. I did have a visit planned with a friend when I suspected DD had CP - I called her up and let her know of my suspicions, and she rescheduled the visit. I do not send sick kids out into the world to establish immunity, because even though I actaully would like to see the return on CP/ rubella, I am not playing God and imposing my agenda on others. Some people do not want their kids to get sick for darn good reasons. That being said, when I was a child (I am pushing 40) almost everyone got CP. I think this is because diseases are often contagious before symptoms set in.