If you are talking ONLY homeschooling, then yeah that was the only one I could really think of off the top of my head. PS kids can read and write and do math and learn manners (maybe not all kids but a good portion do). As long as a kid has parents that care about their education and things they are passionate about then most PS kids have a lot of the same oppurtunities as HS kids, they just don't have as much time for them.
More comunity mindedness, maybe. We have more time to get our kids involved in their comunities and have more oppurtunities to teach them about being a part of a community and how they can help.
In many cases I think they take a bit of the burden off of over-taxed school districts. Here our class-size is determined by how many kids are in the grade. They always have 2 teachers. So this year there are 6 homeschooled 3rd graders which means the classes are 18 instead of 21, a bit more manageable.
Also we have time to be more community minded. I still help with the PTA, help buy books for the school library, Help plan the soccer banquet, etc. We are members of a co-op that does a play each semester and the second graders and 5th graders from the local elementaries come to the playhouse for awesome (free) field trips!
I have read statistics that say homeschool children are more involved in community projects, give more to charity's & are more involved with voting & the political system them public or even privet schooled individuals.
I think raising kids that don't just follow the crowd is a benefit. We need people that will have moral standards (whatever those may be) and not just base their moral code on what is around them.
I think homeschooling also has the potential at raising up the occasional "genius" child at something. Will every home educated child be a genius, no... and I'm sure some are public schooled. However, as home educators, we know that kids like this have more of an opportunity to shine sometimes at home than in public school. Who knows what awesome inventions and advancements can come from homeschooled kids?
Another benefit? Well, it's pretty base but... I pay taxes to the schools (gladly) and my kid doesn't use that money. It all goes to the other kids and the school.
It depends on the family and the kids. Advanced kids can move along quickly, maybe quicker than they could in a PS. Slower kids can learn more because they can take more time with a subject, without being rushed through like they might be in a PS. So society will end up with people who have learned more than they would have in a Public School, and those people will be better prepared to function productively in society than they would have been if they had to try to learn at the pace of the rest of the students in their local Public school.