Non-public ("private") school detractors, who are typically public school boosters, often claim that such schools are inherently evil / amoral / wicked because they are not "accountable" in the same way as are public schools. While in a very narrow sense this may be true, it in nonetheless rubbish.
Non-public schools do not answer to the general public, they answer to their community which is of course a result of their funding and control. Their community and what they offer is defined and limited by and evident from their Mission. If a non-public school does not meet its Mission, it will lose its community and it will fail.
Some non-public schools focus on college preparation and these schools proudly and widely announce their college acceptances, alumni successes and, increasingly, the extent of financial aid their alumni have been offered.
Some focus on examination success, some on sporting prowess and some even on an equestrian program. Again, these schools state clearly on their signage, websites and in their admissions materials in what it is that they specialize and how well it is that they do. If they do what they say they will do, they attract and retain students, they succeed in fundraising and they receive donations. These schools are fully and completely accountable.
Conversely, while public schools are theoretically accountable to the public, realistically they are accountable to their political masters ("follow the money"). Their reporting lies only in terms of the then current political whims such as test scores, absences, vandalism, teacher salaries and so on. I am not saying public schools are inferior. I do believe that in their mandate to be all things to all people they are set up to face significant challenges.
However, I do reject outright the claim that non-public schools are unaccountable.