I haven't ever homeschooled myself, but I've had quite a few homeschooled children take part in groups I've led, and my experience has been the opposite - the homeschooled children that I've had have instead often been quite adept at understanding acceptable social behavior and are able to navigate social nuances as well as the other-schooled kids
A school can worsen manners (I'm not sure what "social skills" means) if it tolerates misbehavior by students. I went to a good suburban high school. I remember once going to a lower-track English class to take a test for another class with the same teacher. I was surprised by the chaotic environment. The boys in the back of the class loudly carried on their own conversations, which the teacher must have noticed but ignored. This never happened in honors classes. In urban schools the behavior tolerated can be much worse.
If you disrespect your boss at a meeting in this way, expect to be fired. These boys were being DE-socialized.
