rational: The best learning boys will hold out for the most money.
This is indeed an old system, but does it make sense now? We used to have a small number of Talmidei chachamim who were able, and wanted, to learn full time and a small number of very rich people and lots of very poor. Now, we have much larger professional middle class and a high cost of living – who can have comfortable lifestyle by working, but not enough to support several sons-in-law.
what is thenn the motivation of the multitude of learners (except the true top ones), select a life partner based on money, instead of learning how to support themselves. I they are that bright and kodesh, they could work in a profession 2-3 hours a day, it will be enough to modestly support their families.