Saint Benedict ran a monastery. He ran into the problem that many monks wanted to spend all their time praying and studying, and not do any of the dirty manual labor — housekeeping, tending livestock, working in the fields — needed to keep the place going. So he adopted and enforced the motto, Laborare est orare — “Work is prayer.”
In excess, religious study can become a drain on society’s resources. Many Haredi, or “ultra-orthodox,” men in Israel want to spend all their time in religious study instead of earning any money. (Article.) Meanwhile, a majority of them live on welfare, with eight to fifteen children. This places a burden on the remainder of society that that economy can no longer bear.