Squeak, for one, they person who gets a good education is less likely to need to rely on others (wether scholarships, medical assitance, food stamps, section 8, gmachs etc).
And technically, I could bus my kids to Staten Island to recieve a decent education (far better than schools in Lakewood IMHO) and dave about 50% of tuition costs. I just don’t want to bus my kids.
A person with little secular education has less choices. In order to command the type of salary to put 9 kids through school, you need a strong background and a good job. The percentage of those in the yeshivish community is smaller than in MO circles. I would say they are probably relying on breaks to come out to zero.