A lot of public schoolers basically just don't understand the benefits. I'm not saying this for everyone though. A lot of kids became successful through public schooling.
It's simply easy for some to make sweeping generalizations and feed on stereotypes.
You will have your good Homeschoolers and your bad homeschoolers. It either makes you socially awkward or more socially desirable. School isn't just about being social though and many forget that.