It depends why they're home schooled. Some people homeschool because for whatever reason they have the time and desire to and are unsatisfied with the quality of a public school education.
Others are stupid as fuck and ignorant and want their kids to grow up ignorant, so they homeschool to protect their kids from "evilution" and make sure they grow up not only with their general religion, but exactly their religion in every respect, with no pollution from outside ideas.
The latter are why homeschoolers have a bad reputation.