My primary reasons for not vaccing (and I bring it up as it hasn't been mentioned), is that I don't believe mealses, mumps, rubella or chicken pox are life threating to my children.
Immunosuppressed children etc, yes, but mine are not. These are all treatble diseased, Rubella is very, very, mild and only a danger to pregnant women.
If and when my children get sick they are cared for at home until they are not contagious. This is also one of the main reasons I am a SAHM (as much as possible). I don't want the pressure of taking 2 weeks off work with an employer on my back.
Every single child I know who has contracted anything major (since I started investigating this a few years ago) have ALL being "immunised". So why bother risking injecting children with crap cultured off monkey kidneys?

Anyway, that's my thing - I think people are frightened by what I consider 'normal' childhood illness, many we have contracted ourselves.