None of the 3 homeschoolers we had had any disabilities. One was a fundamentalist christian, so they homeschooled for that reason. It wasn't clear to us why the other two homeschooled- one boy couldn't read by the end of first grade. They all dropped out by third grade from cub scouts b/c they were "too busy."
I surf on a homeschooling 2 college website, although we don't homeschool. I think if you homeschool high school and the child wants to go to a very competitive college, they need to have very good SAT and other scores, National Merit finalist status, etc. Alot of them seem at that point to go to community college anyway, so although it's not "high school," it's not so much "homeschool."
It's gotten so difficult anyway to get into college! Out here in california, the average GPA on a 4.00 scale to get into the mediocre university of California schools (NOT Berkeley) is 4.20! Incredible!