The value to society is not with a public schooled child, but with an educated child, regardless of the source of his education. If that can be done by religious people, it's just the same to me. If the problem is with the qualifications of the teachers, then let's address that. With the failures seen in the public school system, it seems ironic to me that anyone would be going after the private schooled kids. These parents want to use a small portion of the per child allotment to get their children a real education.
The fact that my own children get an adequate schooling under the PS system is utterly irrelevant to those who aren't. (The school system was one of the main factors affecting our move to this area.) The fact that I (and the rest of us probably) can afford computers, etc., is likewise irrelevant. My kids would be educated regardless of what my income is. My kids came to school anxious and ready to learn. They were completely brainwashed into believing that school was a great adventure. (I underplayed the boring parts.)
Again, I use the public school system. The state takes my money (they take whatever they want, might always making right) and they provide whatever it is they provide and I figure I might as well make use of the service, especially since the teachers my kids have seem marginally competent (and the particular teachers right now especially good). However, we did consider private or home-schooling once when the school investigated us without our knowledge. I was pretty irate at the time since they wouldn't tell us who had accused us (the constitution is null and void when it's inconvenient); however, in retrospect the principal saved our family a lot of misery by not immediately turning it over to the jackboots. Still, I'm very glad that I have a choice. We could afford private school, but why pay twice?
Until this year when my health problems became so severe I couldn't ignore them any more, I was a volunteer tutor at a local high school. I spent many, many hours helping kids learn algebra, physics, but mostly geometry. The biggest problem is failure to study - more important to talk on the phone, party, and hang out. I don't have a desire for other people's kids to do badly, no matter how incompetently they raise them. But it would be nice if, were the school system to begin to fail my kids, they not do everything in their power to prevent my kids from achieving. My opinion is that if the people who were complaining about this stuff spent as much time concentrating on education as they did on whining there wouldn't be any education problem.
Here's a story. I have this neighbor who is a really religious guy. Now, I'm a really, REALLY strong atheist. I just have no use for religions at all. But I get along with this guy. We just don't discuss it. He started a chess program at the elementary school a few years back and he's gotten phenomenal feedback. I was president of the Ft Knox Chess club decades ago and there were only 4 or 5 people who would show up every week. The U of L chess club (of which I was not a member) would have maybe a dozen or so people show up at meetings. This elementary school regularly has 20 to 30 people show up. This guy is really great. So he takes his kids out of PS and his wife starts homeschooling them. I don't know if she has any college, but she's much smarter than most of the teachers at that school. Things go well for them, but HE CONTINUES TO COACH CHESS AT THE SCHOOL. (Bear in mind, he doesn't think he should get a voucher for this, but I very strongly do.) After 9/11 he loses his job. He's out of work for months, but HE CONTINUES TO COACH CHESS AT THE SCHOOL. This is amazing to me. Life has got to be really hard for him, but he's committed to these kids - he's committed to MY kids (my youngest is in the chess club). I mention this as anecdotal evidence against the misimpression that people have that people who homeschool or use private schools are selfish. This applies to some precious few of them, if any.
It's true that having an educated society benefits us all, but I see no value in looking at things in extreme terms - that somehow we have to reach every, single "child." There are plenty of opportunities for most people to succeed if they want to.
As an aside, it struck me some years ago that public school has two purposes. The first is to raise the bar for the worst performers. The second is to lower the bar for the top performers. This became evident to me when the NCTM asked for comments on their Principles and Standards, which they have since adopted. I considered writing them a long note, but I only had a month and that wasn't long enough to craft a serious letter. It was a good thing I didn't waste my time, too, because I saw their responses to the responses they got from others. It turns out that this is more of a social manifesto than a standard. I'm not sure what kind of influence these guys actually have on the PS, but it would be hard to believe they will be ignored.
So long as the PS provides adequately for my kids, I'll keep them there. If they fail, I'll make other arrangements, hopefully including vouchers (which are not unconstitutional).