This matter really depends on the country you're coming from, and how well funded public schools are. Speaking of my native Brazil:
|1. One flaw with private schooling is that schools have a financial incentive not to fail students, and without the risk of failure students may be less motivated to learn and do well in their classes.|
It's the opposite in Brazil, where government has a system put in place that in public schools, no student can ever be failed, they must always be moved forward no matter the grades. Due to a lack of funding, the teachers are underpaid, students fail to learn, turning classes into a waste of time for a part of them, which leads to unrest and all that comes with it, and reduces motivation to learn. Whereas in private school, where parents are paying a good amount of money, they also attempt to instill that motivation in their kids, and since the environment is considerably better, there's less disincentive to motivation.
|2. A second problem with private schooling is that, all other things equal, colleges regularly think higher of a student who went to private school over one who went to public school giving them an unfair advantage.|
In Brazil, colleges don't care where you're coming from. Private colleges won't care as long as you can pay the tuition fee, and public colleges won't care as long as you pass their entry exam. Your fellow students might care, but it's not very often that that happens.
|3. Another problem with private schooling is that students (or rather their parents) pay extensive fees for education, which can leave them with the misconception that they are being educated more, leaving them to think less of their publicly taught peers.|
In Brazil, they are getting educated more and better. Now the "thinking less of their publicly taught peers" is not something that happens due to private schooling, but it's a failing of character on the person. I used to think less of some of my privately taught peers due to the lackadaisical attitude towards class, and I used to think more of the publicly taught peers who managed to overcome difficulty and get into a good college, because I know, in Brazil, how hard a time they had and how smart they must be to overcome it.
|4. A fourth problem with private schooling is that a classroom can't have a diverse range of students or a broad set of opinions if everyone there is paying tens of thousands of dollars in tuition. This leads to an inferior education.|
What sort of diversity are you talking about? You can find a broad set of opinions regardless of where a person has come from, financially wise.
|Some argue that private schooling is important because it provides a second option in areas where the public schooling is sub-par, however I would argue that if one lives in an area where they can afford private schooling they probably also live in an area where the public school system is just fine.|
What are you basing your argument on?
My points, of course, depend on where you're coming from. If you're talking about a first world country, with an amazing public schooling system, then sure, private education might be a waste of money for the parents. But in a large part of the world, that is not so. Private education can provide for quality in those countries, as well as provide a "better" education in terms that they do not have to conform to a political agenda in regards to what they teach. I've frequented private schools my entire life, and never had any classes on religion or any sort of creationism or whatever, and was also given proper information regarding the country and the world, whereas in public schools throughout Brazil you'll find that they have an obligation to provide "religious studies", even though the country is supposed to be secular, or non-religious, as well as misinformation on the study materials due to oversight or the government's intention to spread propaganda.
I don't see it as immoral at all.