I think the vast majority of parents have confidence that their childrens’ yeshivos and BYs do a reasonably good job of spending efficiently; there will always be malcontents, and exposing the budget won’t help much.
OTOH, there are major privacy concerns in exposing the schools’ finances; the staff has a right to privacy regarding their salaries, and parents have a right to privacy regarding their personal finances. It’s demeaning enough (although necessary) for 50% (or more) of parents to have to show their income and expenses to a tuition board. Must their finance become public knowledge?