Everything about the education monopoly we dread is a manifestation of the government's funding monopoly. So if it's wrong fundamentally, distributing it a little wider won't make it right. Which brings us to vouchers. I do not oppose vouchers because they will burden private schools with onerous regulations, or because they will lead to the secularization of religious schools, the homogenization of private and alternative schools, weakened families, the expansion of the unions, increased costs, and yes, decreased test scores. Those are merely the inevitable results.
Vouchers are wrong because they make the same bad choice as government schooling.
Vouchers fully embrace the error of government funding of education. To carry out your duty as a parent, you must own the means to produce the education for your children, whether by contracting out or doing it yourself. My wife and I home school our children, but we don't feel more responsible than our friends who send their kids to our parish school. Just being a shopper, however, does not make you an owner. Look at food stamps and housing vouchers.