...
Tax revenue likely took a hit with so many people moving out.
Individual schools and districts get $$ based on Average Daily Attendance. So whether students move out of the city, transfer to private schools, or homeschool (non-PS, of course), declining ADA means less $$.
Reduced ADA is the reason PS people don't like homeschooling and private schools, the decreased ADA $$. The private and home schooling parents don't pay a dime less in taxes than similarly situated PS parents.