Being a homeschooler now for the past 2 years, I've found this is a model many homeschoolers use, and find great success with it. It's hard though, in our society, w/ the comparisons... "hey, my little johnnie in school can recite his times tables in 1st grade... what about your homeschooled kid?" type of thing.
It's like a competition, whose child can spew out facts at the earliest age... flash cards for infants, your baby can read, the list goes on and on. Our society is getting crazy w/ the younger the kid can do something, the better, when in reality it can actually cause problems down the road.
And learning styles are pretty much ignored, which is the most important aspect of learning. Someday, maybe, our schools will change w/ the times. Until then though, children who don't fall right in the middle/average of everything, are going to need their parents to fill in all of the many gaps they'll encounter, because like someone else posted, with budget cuts in schools, they just don't have the resources.
One of the many reasons we starting homeschooling.