Once upon a time, copyright infringement for personal use was barely a crime, while copyright infringement by a for-profit commercial enterprise was a serious matter.

The idea being (before the rise of online peer-to-peer piracy) to prosecute the people making bootleg VHSes rather than the people buying them.

With the rise of these AI behemoths, it seems that rule is now inverted: You can download all the pirated ebooks you want, as long as it's for large-scale for-profit commercial use.

Nothing is inverted. OpenAI was never engaged in any sort of distribution of pirated copies.