As someone else pointed out, it's not clear that school helps with this. The kid who went to school and didn't learn this is not at all an outlier. There are quite a few in every class. What would be interesting is if there is research to indicate which suffers more: The kid who doesn't learn this and has to go through school, or the homeschooled kid who doesn't learn this and doesn't have to deal with it in school.
Agreed on the tutor thing at high school, although for many homeschooled kids I know, it was usually one of:
1. Send kids to a regular high school (i.e. don't home school those years)
2. Lots of schools in this area have programs that allow homeschooled kids to attend classes in the areas their parents cannot teach. Of course, rules on this vary from state to state.