MMR shouldn't be a debate even, it should be left up to the parents. If their child is sickly, they might want the vaccine but healthy children can tolerate measles, mumps, and rubella very well. I had all three when I was a child and I'm the healthiest person I know --besides my kids. Anyone who would refuse the polio vaccine would be an idiot I think ---when you see someone with post-polio syndrome and the life they endured after suffering through polio, you wouldn't want to risk that one.
Careful, you may be on thin ice with the medical thought police around here. :-)
But you're right of course. I had measles and mumps, but not rubella. Actually, I had measles and pneumonia at the same time. That put me in the hospital for a few days when I was seven.
In fact, I seem to have read somewhere that measles has never been particularly fatal to children in developed countries. Combined with poor nutrition in 3rd world countries, I'm sure it's quite dangerous, as would a lot of other things.