Without having to meet the same requirements like attendance and grades, its doesn't seem apples to oranges.
I knew a family who home schooled until 8th grade with kids who were big in little league and Pop Warner football standouts, then sent their kids to public high school and supplemented with further homeschooling, so that their kids could play on the high school football team. It doesn't seem like that's an unreasonable expectation.
Yes, it might be, if you didn't think the public high school academic environment was doing active harm to your children. Being exposed to an all-day booby hatch is a high price to pay for a football program. Having to supplement that indoctrination with after-hours, after-football homeschooling is just excremental icing on the frankly-inedible cake.
(I should apologize for being so vehement... as you might imagine, I can get kind of passionate about homeschooling. Sorry.)