They dont owe anything to the system in the first place for you to make a logical claim that they are robbing the system. Furthermore, their competition will go much further towards improving public schools than being victimized and sending their children to be victimized in a public school. Child crusades dont work.
Home schoolers actually make the life of education bureaucrats much easier.
The bureaucrats take the home schoolers' tax money without the burden of providing any educational service. So, if everyone home schooled I think public schools would still exist but the administrators would have bigger salaries since they wouldn't have to pay teachers anymore.
I’m for vouchers.