I think the important thing to note is that the cause for many of the stereotypes is not homeschooling, but rather a parenting style that is very attracted to home schooling.

I noticed this important difference because I participated in and then worked for a Christian Ballroom Dance Cotillion, for 9 years. It started off as a social activity that was dreamed up by home schooling parents who wanted to prepare their children for upper class society. The initial population was actually quite normal, with a wide variety of personalities (my older brothers went the fist year and I started the second).

Over time the program attracted a more conservative population, including many of the "I wear jean jumpers I made myself and love horses" home schoolers. This population included some people who were fairly awkward in such a social activity, but they certainly gained a lot from it. More interestingly by the 5th year we were only about 40% home schooled, and you could pick out a "stereotypical" home schooler easily and ask them how long they've been home schooled only to find out they have been to public school all their life.

By the 7th year I was loosing my interest in the program as it grew more judgmental and socially restricting, and was probably 60% sheltered, and most of them not home schooled.

Now, (two years after I left) my sister was interested in doing it and signed up. Wow... Very restrictive on what is "modest" (my sister almost had to put on a pair of ugly floral leggings because the bottoms of he knees showed when she did a spin) The recommendation for the formal balls is to shop at Goodwill or make the dress yourself, and only "lean in" hugs are appropriate (hugs where your tummy touches are inappropriate, and an adult will be quick to tell you that mid hug). There are certainly a lot of home schoolers in that crowd, but many of them are not.

Point being that there is a correlation between homeschooling and social ineptitude, intolerance towards society, etc. but it is by no means the cause. The parents will raise their children as they see fit, and homeschooling only gives parents the freedom to do so in a more active way. Which does have its negatives... but that comes with freedom, if you prefer government regulating how kids are raised... well yeah that is a whole 'nother tangent

And the obligatory statement: As a graduated home schooler I get a lot of "Wait, you were home schooled?" Also my only social deficiency I would claim was self imposed (not getting any romantic experience till I was 23) because I did not want to deal with it yet... And I'm typically noted as being more comfortable standing up and speaking to a group (oral presentation assignments in college were/are cake assignments where you always got 90+ without much effort) and being more thoughtful in how I respond to social interactions.