This goes back to the concept that with skyrocketing QB salaries, it has become prohibitively expensive to develop quarterbacks that can potentially take all of your coaching investment elsewhere. In effect, this addresses the investment risk of developing quarterbacks. Further, and following the economic rules of "supply and demand", if you add 32 "coached up" quarterbacks to the pool, you effectively address the dearth of experienced quarterbacks which inherently drives their salary structures up. Simple economics. Flood the market with a given product and its price will go down. This is a boon for the Geno Smiths of the world where they can find a tolerant, patient landing spot after their original organization has given up on them. For example, it probably saved the professional career of the Jet's Zach Wilson.
In summary, this is purely a fiscal decision and a wise one at that.