Okay, I have been lurking in the hs/us forum for a while, but since my ds is only 14 months, I haven't spoken up. However, dh and I have known that we were going to hs (only recently learning more about us) since before we were married, and I have known it for, well, ever. I have long been having this discussion with family and friends.
I know that hs/us families are not defensive about their decisions, just defending them against common arguments in an effort to educate, but even then sometimes I think we should all just say:
"The burden is on you to justify the terrible educational and social outcomes of your failed system of "education," which has been quite successful, actually, at achieving its original aims. Meanwhile, I will be attempting to create exceptional opportunities for my children, as "normal" (per ps definition) doesn't really cut it."
I could probably be more articulate, but so many others here have done such a good job, in thread after thread, of explaining the specifics.