Always_Ask_Questions,
“not from the point of view of taxpayers”
Who cares what the taxpayers think? I want to know what you think.
“other than classes accredited academically and qualifying for educational subsidies. Maybe, if we behave in a way that Americans see the value of learning and write it in the law and regulations, then it will be great.”
Ah, but they do. There are yeshivos and kollelim that offer academically accredited degrees such as BTL or BTS, and even graduate degrees. Semicha (religious ordination) is also a generally recognized accomplishment in the U.S. that can lead to employment as a clergyman. So if a yungerman was accruing these degrees or working towards semicha while sitting and learning, would that check your productivity boxes?
“Say, one who gets unemployment/welfare can either be learning a profession, search for work, or learn Torah.”
The median income for a 25-29 year old who is the proud and productive recipient of a bachelors degree majoring in humanities or liberal arts is just north of $40,000. The poverty line reaches that income with a household of 7 people, 5 of them being dependent children. So the question you should be asking your taxpayer friends is if it is valuable to the United States for people to get married and have children, and raise them in a culture that produces peaceful, extremely low crime communities with vibrant businesses and lots of travel.