They do get paid for that, however. They get a share of the value of each book sold. Those schools are paying for the books.

There is also the catch that those wet networks are of finite lifespan and are output throttled. This limits the losses caused. A lot of authors also consider improving those networks a big part of why they write.

It's the difference between someone hand drawing a Micky mouse birthday card for their sibling, and hallmark mass producing them for sale. The former is considered acceptable, the latter is grounds for a law suit.