It's not actually difficult to see how this works.

"Piracy" means "doing stuff some particular IP rightsholders (or sometimes, upstream/downstream stakeholders) don't like". The fact that a behavior is "piracy", like the fact that a behavior is permitted by a copyright license, doesn't tell us anything about whether that behavior is pro-social.

One key strand of Aaron Swartz' life work was the expansion, strengthening, and maintenance of the commons of intangible and intellectual goods (a "creative commons", if you will!). The "piracy" he was engaged in before he was harassed and threatened into suicide was an attempt to reclaim for direct and free use by the public the output of collectively funded public research. You can argue that he was operating outside the rules of the system, and that this is anti-social in some sense, but I think the fact that Swartz was also actively involved in copyright reform projects gives him a stronger case that what he was working on was a kind of protest or direct action designed to accompany and further broader reform efforts, not just thoughtless chaos or showboating.

What the frontier labs have done with these copyrighted works is create something for themselves that they then lease the use of to the rest of us for a profit. The same characteristics that make their task "transformative" in the eyes of the courts are the ones that make it opaque to us, that stop it from being part of the commons.

I could say more but I'm tired of typing on my phone on a holiday and, frankly, it feels obvious enough.