Ta-Nehisi Coates was asked what he would say to a high school of black kids. His answer will be very familiar to homeschoolers.
What I generally try to do is avoid messages about "hard work" and "homework," not because I think those things are unimportant, but because I think they put the cart before the horse. The two words I try to use with them are "excitement" and "entrepreneurial." I try to get them to think of education not as something that pleases their teachers, but as a ticket out into a world so grand and stunning that it defies their imagination.
He later summarizes it as "own your education." Mark Twain told us to never let school interfere with our education. It's the same idea.
That is essentially what most homeschoolers do. The parents own the education early on, and by high school the kids frequently own it. This often gets called unschooling. I'm not quite sure how you can unschool in school, but the concept of getting the kids to own their education is important. However, I suspect many will end up frustrated by a standardized test focused education that keeps the writer from spending his time writing, and the engineer from spending his time tinkering. It's easy for us. You want to spend 8 hours every day reading history, or studying horses, or math, or whatever? Fine with me! After the 3 Rs are mastered it's all electives as far as I'm concerned. If only the school system thought that way.
More kids need to hear the message that education is their ticket out, or up, or to wherever it is they want to go. Don't do it for your teachers or parents. Hell, you might have to do it in spite of them.
Do it for yourself. Own your education.