My gut says that homeschoolers overall have more normal-type families than absolute weirdos. However, as a movement, homeschoolers have tended to resent anything that involves government interference with what they do. As a result, we don't have much in the way of meaningful data about how well their kids are doing educationally. I believe that there are only 2 states that require homeschooled students to participate in annual testing required of public school students. And even in those states, it is fairly easy for parents to simply fly under the radar by not making themselves known to the local school board. There are some studies that are frequently quoted by home school advocates, showing that home schooled students do well on college entrance exams. But, these tests are voluntary, so we don't really know if the kids taking them are the tip of the iceberg, middle of the road or fairly representative. And there are advocates who push involved parents to have their students who do well take the tests to demonstrate that home schoolers are better than others.
We really just don't know. But the scary part to me is that we just don't know where the kids are who are being hidden from sight using home schooling as a means of cover.