Why are so many prejudiced against homeschoolers?

I always here comments from people, such as "homeschooling does nothing to teach kids how to get along with each other," and "does not prepare them for higher education". Statistically Homeschoolers score higher on the SATS then Publicly or privately schooled kids. As far as getting along with others; well my daughter is volunteering some her time this summer to build homes for poor families in Mexico, where she will need to work on a team with kids and adults and get along with all of them. She also has to figure out how to deal with younger siblings, friends at church, and just people we run into day-to-day. She has volunteered in other venues before also, and gets along great with other people. Most other homeschoolers we know also have no problem relating. How long do homeschoolers have to keep proving people's umptions wrong before they stop uming the worse?